research article analysis of changes in precipitation and...

Research ArticleAnalysis of Changes in Precipitation and Drought inAksu River Basin Northwest China

Yuhu Zhang1 Wanyuan Cai1 Qiuhua Chen2 Yunjun Yao3 and Kaili Liu2

1College of Resources Environment amp Tourism Capital Normal University Beijing 100048 China2School of Mathematical Sciences Capital Normal University Beijing 100048 China3State Key Laboratory of Remote Sensing Science College of Global Change and Earth System ScienceBeijing Normal University Beijing 100875 China

Correspondence should be addressed to Wanyuan Cai 743483324qqcom

Received 23 October 2014 Revised 15 January 2015 Accepted 11 February 2015

Academic Editor Ming Pan

Copyright copy 2015 Yuhu Zhang et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The analysis of the spatiotemporal trends of precipitation and drought is relevant for the future development and sustainablemanagement of water resources in a given region In this study precipitation and Standardized Precipitation Index (SPI) trendswere analyzed through applying linear regression MannndashKendall and Spearmanrsquos Rho tests at the 5 significance level For thisgoal meteorological data from 9 meteorological stations in and around Aksu Basin during the period 1960ndash2010 was used andtwo main annual drought periods were detected (1978-1979 and 1983ndash1986) while the extremely dry years were recorded in 1975and 1985 at almost all of the stations The monthly analysis of precipitation series indicates that all stations had increasing trendin July October and December while both increasing and decreasing trends were found in other months For the seasonal scaleprecipitation series had increasing trends in summer and winter 33 of the stations had the decreasing trend on precipitation inthe spring series and it was 11 in the autumn At the same time the SPI-12 values of all stations had the increasing trend Thesignificant trends were detected at Aheqi Baicheng Keping and Kuche stations

1 Introduction

Drought is the result of insufficient or lack of rainfall foran extended period which causes a substantial hydrological(water) imbalance Numerous indices have been applied todetermine different drought characteristics depending onthe study purpose Precipitation-based drought indices withprearranged thresholds are valid since the main reason ofdrought is rainfall deficit [1 2]

In the past decade many scientists have analyzed thespatial variability of drought using drought indices andprecipitation characteristics [2ndash8] There were a lot of studieson drought [8ndash13] and various indices have been appliedto measure different drought characteristics depending onresearch goals The study related to precipitation is a pre-requisite for other research studies Analysis of precipitationdata outputs helpful conclusion which will be applied to planand manage water resources system For arid and semiaridregions precipitation is a particularly important factor for

water resources planning and drought risk managementMoreover arid areas propose a challenge due to largecontradistinction between dry and wet conditions within atemporal cycle

The arid region of northwest China is one of the mostsensitive areas in the world in terms of responding to globalclimate change [14 15]The Aksu River Basin is located in thewestern part of the middle southern slope of the TianshanMountains and at the northwestern edge of theTarimBasin inXinjiang Uygur Autonomous Region of northwestern ChinaResearch on drought for this area can contribute to earlywarning and water resource plan Therefore it is importantto research the spatiotemporal trend of precipitation anddrought in the past several decades in the Aksu River Basin

Many scholars have studied the characteristics of precip-itation changes in different regions in China over the past 50years [16ndash20] The major results indicated that precipitationin summer in eastern China shifted southward in the late1970s [21 22] national average precipitation increased with

Hindawi Publishing CorporationAdvances in MeteorologyVolume 2015 Article ID 215840 15 pageshttpdxdoiorg1011552015215840

2 Advances in Meteorology

the increasing precipitation in spring but slightly decreasingin autumn in the last decades [23] and the frequency of heavyprecipitation events increased in China [24] Mechanismshave also been proposed to explain precipitation changes [25ndash27] Affected by decadal changes of the global climate sys-tem precipitation in China is characterized with significantdecadal changes especially since the 1990s and the increasedglobal warming plus the reenhanced East Asianmonsoon arebound to influence the regional precipitation distribution andits changing trend Precipitation changes might greatly affectregional climate stability hydrological processes and wateravailability

Furthermore there have been a number of drought andprecipitation studies for different periods in Aksu RiverBasin Related studies [28ndash35] have indicated that thereis a change about precipitation and drought indices Forexample Chen et al [36] summarized that the streamflowfrom the headwaters of the Tarim River shows significantincrease and is sensitive to precipitation but the streamflowalong the mainstream of the river has decreased Chenet al [37 38] analyzed the fifty-year climate change and itseffect on annual runoff at Aksu River Basin The streamflowshowed a significant increasing monotonic trendThe annualrunoff in the Aksu River had increased by 109 since 1990They also detected the long-term trends of the hydrolog-ical time series using both parametric and nonparametrictechniques based on temperature and precipitation datafrom the past 50 years The temperature the precipitationand the streamflow from the headwater of the Tarim Riverexhibited a significant increase during the last 20 years Leeand Zhang [39] further developed the relationship betweenNAOand drought disasters in northwesternChina Statisticalresults show that NAO and drought disaster were negativelycorrelated as positive modes of NAO caused northward-displaced stronger-than-average midlatitudeWesterlies withan enhanced latitudinal water vapor gradient into the centralAsian drylands resulting in reduced drought frequency andintensity in northwestern China Ling et al [40] investigatedintra-annual runoff trends and periods in the headstreamareas of the Tarim River Basin by nonparametric tests andwavelet analysis The results showed that the runoff airtemperature and precipitation of the headstreams increasedremarkably during both high-flow and low-flow periods

However most of the previous work on a comprehensiveanalysis of trends and variability using statistical test anddrought indices in precipitation series over Aksu River Basinis still lacking Thus it is necessary to analyze the trend ofprecipitation and characteristics of drought to explore thecauses and the formation mechanism of Aksu River Basindrought which is vital for drought forecast defense andmitigation The analysis of drought variability can improvewater resources management in the area

The main goals of the study were to study variability ofprecipitation on monthly seasonal and annual time scalethrough applying the linear regression MannndashKendall andSpearmanrsquos Rho methods to assess precipitation predictionfor the Aksu River Basin in China and to analyze the impactof serial correlation in detecting trends and to investigate thedrought in study area from 1960 to 2010

2 Materials and Methods

21 Study Area and Database The Aksu River Basin (75∘35ndash82∘001015840E 40∘17ndash42∘271015840N) is located in the western part ofthe middle southern slope of the Tianshan Mountains andat the northwestern edge of the Tarim Basin The totalarea is 514 times 104 km2 of which the area of the regionin China is 31 times 104 km2 The basin is in the interior ofthe Eurasian continent Vast territory diverse topographycomplex terrain and typical regional climate variationsmadeup the characteristics of the northwest mountain climateIt has lower temperatures plentiful precipitation and agedsnow in the high mountain zone while the middle mountainzone brings about changes in temperature clearly and isthe largest precipitation distribution area The low mountainzone suffers from drought large temperature changes and isfairly well in heat conditions Due to the Taklimakan Desertin the south and the Tianshan Mountains in the north thecool air and vapor derived from Central Asia Siberia andArctic Ocean do not straightly enter into the southeasternplain region which causes typical temperate continental dryclimate regional characteristics such as minimal precipita-tion intense evaporation adequate sunshine and extremeheat [41]

Daily precipitation saturation vapor pressure net radia-tion soil heat flux density temperature average 24 h windspeed at 2m height and vapor pressure data were collectedfrom 9 meteorological stations distributed in study area(shown in Figure 1) for the period 1961ndash2010 and wereobtained from meteorological data shared in service systemof China (httpdatacmagovcn) Seasons were defined asfollows winter = December January and February spring =March April and May summer = June July and Augustand autumn = September October and November Thegeographical location of the selected meteorological stationsis presented in Table 1

The precipitation datasets were investigated for homo-geneity and absence of trends The autocorrelation analysiswas applied to the monthly precipitation time series of eachstation The precipitation data were quality controlled (QC)from [42]

22 Rainfall Variability Index (RVI) RVI (120575) is calculated asfollows

120575119894=

(119875119894minus 120583)

120590

(1)

where 120575119894= Rainfall Variability Index for year 119894 119875

119894= annual

rainfall for year 119894 and 120583 and 120590 are the mean annual rainfalland standard deviation for the period of the year 1961ndash2010A drought year occurs if the 120575 is negative

According to WMO [43] rainfall time series can beclassified into different climatic regimes

extreme dry 119875 lt 120583 minus 2 sdot 120590

dry 120583 minus 2 sdot 120590 lt 119875 lt 120583 minus 120590

normal 120583 minus 120590 lt 119875 lt 120583 + 120590

wet 119875 gt 120583 + 120590

(2)

Advances in Meteorology 3

Peoplersquos Republic of China

Kyrgyzstan

NEW

S

Synotic stationsNational bountaryAksu River Basin

DEM

Low 173High 8354

Kashi

Baicheng

KepingAheqi

AlarAksu

Kuche

WuqiaTurgat

Peoplersquos Republicof China

(km)0 75 150 300

46∘N

44∘N

42∘N

40∘N

38∘N

46∘N

44∘N

42∘N

40∘N

38∘N

75∘E

75∘E

80∘E

80∘E

Figure 1 Location map of the 9 synoptic stations in Aksu RiverBasin of China

Table 1 Location of the stations

Site name Code Lat (N) Long (E) Elev (m)Aksu 51628 41 10 80 14 1105Aheqi 51711 40 93 78 45 1986Alar 51730 4055 8127 1012Baichen 51633 4179 819 1229Keping 51720 405 7905 1162Kuche 51644 4172 8297 1082Turgat 51701 40 31 75 24 3507Wuqia 51705 3972 7525 2176Kashi 51709 39 28 75 59 1291

23 Aridity Index (AI) In this study we employed AridityIndex [44] to quantify the drought occurrence as a numericalindicator of the degree of dryness of the climate at eachstudy location According to the ratio of precipitation (119875) topotential evapotranspiration (PET) regions were classifiedfrom extremely arid to humid PET was calculated usingthe FAO Penman-Monteith method widely [45] It can becalculated as [46]

PET =

0408 sdot Δ sdot (119877119899minus 119866) + 120574 sdot (900 (119879 + 273)) 119880

2sdot VPD

Δ + 120574 sdot (1 + 034 sdot 1198802)

(3)

where PET = potential evapotranspiration (mmdayminus1) Δ =slope of the saturation vapor pressure function (kPa∘Cminus1)119877119899= net radiation (MJmminus2 dayminus1) 119866 = soil heat flux density

(MJmminus2 dayminus1) 120574 = psychometric constant (kPa∘Cminus1) 119879 =

mean air temperature (∘C) 1198802= average 24-h wind speed at

2m height (msminus1) and VPD = vapor pressure deficit (kPa)The locations were then classified as extremely arid

(119875PET le 005) arid (005 lt 119875PET le 02) semiarid(02 lt 119875PET le 05) subhumid (05 lt 119875PET le 065) orhumid (119875PET gt 065) [2 47]

24 Drought Indices Drought indices are themost indispens-able elements for drought analysis and monitoring since theyenable identification and quantification of droughts Therehave been numerous drought indices such as StandardizedPrecipitation Index (SPI) the Palmer Hydrological DroughtIndex (PHDI) Standardized Precipitation Evapotranspira-tion Index (SPEI) the Surface Water Supply Index (SWSI)Palmer Drought Severity Index (PDSI) and the StandardizedAnomaly Index (SAI) The establishment of unique anduniversally accepted drought indices does not exist althougha number of drought indices have been proposed [13 48 49]

In this study the SPI was applied because of its goodcharacteristics in drought identification and prediction ofdrought class transitions [8ndash10] During the first decade of the21st century the Standardized Precipitation Index (SPI) waswidely used And it is simple and considers only precipitationdata which can be found nearly everywhere

241 Standardized Precipitation Index The StandardizedPrecipitation Index (SPI) was proposed by McKee et al [5051] to indicate the precipitation deficit at different time scales(ie accumulated over given time spans) The SPI is a proba-bility index that involves only precipitationThe probabilitiesare standardized so that an index of zero indicates the meanprecipitation amount The relative simplicity of the SPI isone solid advantage of the index [52] The main criticism tothe SPI is that its calculation is based solely on precipitationdata not considering other variables that determine droughtconditions such as temperature evapotranspiration windspeed or the soil water holding capacity

Calculating the SPI for a certain time period at anyplaces requires completed monthly data for the quantity ofprecipitation at least 30-annual sequence [53 54]

SPI ismathematically based on the cumulative probabilityof some precipitation recorded at the observation postResearch has shown that precipitation is subject to the lawof gamma distribution [55ndash57] One whole period of obser-vation at one meteorological station is used to determinethe parameters of scaling and the forms of precipitationprobability density function

119892 (119909) =

1

120573120572

sdot Γ (120572)

119909120572minus1

sdot 119890minus119909120573

119909 gt 0 (4)

where 120572 = form parameter 120573 = scale parameter 119909 =precipitation quantity Γ(120572) = gamma function defined by thefollowing statement

Γ (120572) = int

infin

0

119910120572minus1

119890minus119910

119889119910 (5)


Parameters 120572 and 120573 are determined by the method ofmaximum probability for a multiyear data sequence that is

120572pro =

1

4119860

(1 + radic1 +

4119860

3

)

119860 = ln (119909sr) minussum119899

119894=1

ln (119909119894)

119899

120573pro =

119909sr120572pro

(6)

where 119909sr is the mean value of precipitation quantity 119899 isthe precipitation measurement number 119909

119894is the quantity of

precipitation in a sequence of dataThe acquired parameters are further applied to the deter-

mination of a cumulative probability of certain precipitationfor a specific time period in a time scale of all the recordedprecipitationThe cumulative probability can be presented as

119866 (119909) = int

119909

0

119892 (119909) 119889119909 =

1

120573

119909propro Γ (120572pro)

int

119909

0

119909120572prominus1

119890minus119909120573pro

119889119909

(7)

Because the gamma function has not been defined for 119909 =0 and the precipitation may be up to zero the cumulativeprobability becomes

119867(119909) = 119902 + (1 minus 119902)119866 (119909) (8)

where 119902 is the probability that the quantity of precipitationequals zero which is calculated using the following equation

119902 =

119898

119899

(9)

where 119898 is the number which represented how many timesthe precipitation was zero in a temporal sequence of data and119899 is the precipitation observation number in a sequence ofdata

The calculation of the SPI is presented on the basis of thefollowing equation [58ndash60]

SPI =

minus(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 0 lt 119867 (119909) le 05

+(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 05 lt 119867 (119909) le 10

(10)

where 119905 is determined as

119905 =

radicln 1

(119867 (119909))2

0 lt 119867 (119909) le 05

radicln 1

(1 minus 119867 (119909))2

05 lt 119867 (119909) le 10

(11)

And 1198880 1198881 1198882 1198891 1198892 and 119889

3are coefficients whose values

are [58ndash60]1198880= 2515517 119888

1= 0802853 119888

2= 0010328

1198891= 1432788 119889

2= 0189269 119889

3= 0001308

(12)

Table 2 Drought classification of SPI

Drought class SPI valueNondrought SPI ge 0Near normal minus1 lt SPI lt 0Moderate minus15 lt SPI le minus1Severeextreme SPI le minus15

The drought classification of SPI is presented in Table 2that grouped the severe and extremely severe drought classesformodeling aims since transitions referring to the extremelysevere droughts are much less frequent than those for otherclasses [9] The SPI on shorter time scales (eg 3 and6 months) describes drought events affecting agriculturalpractices In this study the SPI at 12-month time scale wasselected and analyzed because it is more suitable for waterresourcesmanagement purposes in a certain region andmoreappropriate for identifying the persistence of dry periods[8 10 13 61 62]

According to the criteria of McKee et al [50 51]severe and extreme droughts corresponding to the categoriesrespectively are as shown in Table 2

25 Statistical Methods Many statistical techniques (para-metric or nonparametric) have been developed to detecttrends within time series such as linear regression Spear-manrsquos Rho test MannndashKendall test Senrsquos slope estimatorand Bayesian procedure [63ndash68] In this study the MannndashKendall and Spearmanrsquos Rho tests were used to analyze theprecipitation trends while the linear regression was used tocalculate magnitude of trends

251 MannndashKendall Trend Test The MannndashKendall teststatistic 119878 [69 70] is calculated as

119878 =

119899minus1

sum

119894=1

119899

sum

119895=119894+1

sgn (119909119895minus 119909119894) (13)

where 119899 is the number of data points 119909119894and 119909

119895are the data

values in time series 119894 and 119895 (119895 gt 119894) respectively and sgn(119909119895minus

119909119894) is the sign function determined as

sgn (119909119895minus 119909119894) =

+1 if 119909119895minus 119909119894gt 0

0 if 119909119895minus 119909119894= 0

minus1 if 119909119895minus 119909119894lt 0

(14)

In cases where the sample size 119899 gt 10 the mean andvariance are given by

120583 (119878) = 0

1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5) minus sum119898

119894=1

119905119894(119905119894minus 1) (2119905

119894+ 5)

18

(15)

where 119898 is the number of tied groups and 119905119894denotes the

number of ties of extent 119894 A tied group is a set of sample datahaving the same value


In the absence of ties between the observations thevariance is computed as

1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5)

18

(16)

The standard normal test statistic 119885119878is computed as

119885119878=

119878 minus 1

radic1205902

(119878)

if 119878 gt 0

0 if 119878 = 0

119878 + 1

radic1205902

(119878)

if 119878 lt 0

(17)

Positive values of 119885119878indicate increasing trends while the

negative 119885119878shows decreasing trends

Testing of trends is done at a specific 120572 significance levelIn this study the significance level of 120572 = 005 was used Atthe 5 significance level the null hypothesis of no trend isrejected if |119885

119878| gt 196

252 Spearmanrsquos Rho Test Spearmanrsquos Rho test is nonpara-metric method commonly used to verify the absence oftrends Its statistic 119863 and the standardized test statistic 119885

119863

are expressed as follows [71 72]

119863 = 1 minus

6sum119899

119894=1

(119877 (119883119894) minus 119894)2

119899 (1198992

minus 1)

119885119863= 119863radic

119899 minus 2

1 minus 1198632

(18)

where 119877(119883119894) is the rank of 119894th observation 119883

119895in the time

series and 119899 is the length of the time seriesPositive values of 119885

119863indicate increasing trends while

negative 119885119863show decreasing trends At the 5 significance

level the null hypothesis of no trend is rejected if |119885119863| gt 208

253 Serial Autocorrelation Test To remove serial correla-tion from the series von Storch andNavarra [73] suggested toprewhiten the series before applying the MannndashKendall andSpearmanrsquos Rho tests The lag-1 serial correlation coefficientof sample data 119909

119894(designated by 119903

1) is computed as [74 75]

1199031=

(1 (119899 minus 1))sum119899minus1

119894=1

(119909119894minus 120583 (119909

119894)) sdot (119909

119894+1minus 120583 (119909

119894))

(1119899)sum119899

119894=1

(119909119894minus 120583 (119909

119894))2

120583 (119909119894) =

1

119899

119899

sum

119894=1

119909119894

(19)

where 120583(119909119894) is the mean of sample data and 119899 is the sample

sizeFor the two-sided test Unkasevic and Tosic [68] recom-

mended that the 005 significance level for 1199031can be computed

by

1199031(005) =

minus1 plusmn 196radic119899 minus 2

119899 minus 1

(20)

where 119899 is the sample size

3 Results and Discussion

31 Summary of Statistical Parameters Statistical parametersof monthly precipitation time series at 9 synoptic stationsduring the period 1960ndash2010 are summarized in Table 3The minimal monthly precipitation is 0mm for all stationsThe mean monthly precipitation is ranged from 4076mmto 20554mm Moreover it is obvious that 3 mountainoussynoptic stations in the northwest (Aheqi Turgat andWuqia)had the highest mean monthly precipitation

The highest kurtosis of the precipitation values wasobserved at Aksu station with 16699 while the lowestkurtosis of 2682 was found at Turgat This phenomenonindicated that themonthly precipitation in Turgat is relativelyhomogeneous But it is converse in Aksu

Time series of annual precipitation at the 9 synopticstations are shown in Figure 2 The results indicated thatthe annual precipitation had a certain degree of varianceduring the observed period In Aksu Alar Kuche andKashi the annual precipitation is relatively low and basic byabout 50mm However the annual precipitation in AheqiWuqia and Turgat is above 200mm In addition the annualprecipitation in Baicheng Kuche and Keping has obviousupward trend during the observed periodThese results showthat the precipitation in upstream of Aksu basin is larger thanthat in downstream

32 Aridity Index The estimatedUNEPAridity Index for the9 synoptic stations is given in Table 4 The FAO-56 PenmanndashMonteith equation as a part of the model based on service-oriented paradigm [76 77] is used for estimating PET Theresults indicated that the Aridity Index ranged from 0048 atthe Alar station to 0397 at the Turgat stationTheAlar stationis extremely arid and the Aheqi station and the Turgat stationare semiarid while all other stations are aridThe upper limitfor extremely arid climate is 005 but Alar had a slightly lowervalueTheAlar station is extremely arid because of the highestPET minimum of the annual precipitation and the highestvalue of the temperature difference

33 Rainfall Variability Annual rainfall variability indicesfor the observed synoptic stations are shown in Figure 3while the percentage distribution of dry normal and wetyears during the period 1960ndash2010 is given in Figure 4 It isobvious that there was no extremely dry year for all stationsAlthough considering both time series of precipitation andannual rainfall variability indices for the 9 synoptic stationsthere were two main periods which were characterized bylong and severe droughts namely 1978-1979 and 1983ndash1986

During the first period the drought years were approx-imately 55 of the total years The second period is char-acterized by approximately 47 of the drought years Inaddition it should be noticed that there were 4 dry years1961 1975 1985 and 2007These four years were characterizedby approximately 89 negative values of the annual rainfallvariability index

34 Analysis of Precipitation The serial correlation coeffi-cient can improve the verification of the independence of


Table 3 Statistical parameters of monthly precipitation time series at 9 synoptic stations during the period 1960ndash2010

Station name Min (mm) Max (mm) Mean (mm) Standard deviation (mm) CV () Skewness KurtosisAksu 0 922 6162 10148 164672 3343 16699Aheqi 0 1452 17920 23597 131676 1983 4520Alar 0 509 4076 7546 185139 2737 8473Baicheng 0 768 9920 12367 124664 2115 5874Keping 0 812 8029 13348 166253 2553 7537Kuche 0 653 5818 8832 151812 2499 7620Turgat 0 1221 20554 21380 104015 1615 2682Wuqia 0 1216 15009 18471 123071 1878 4080Kashi 0 785 5615 9561 170283 3099 12861Note cv-coefficient of variation

Table 4 Aridity Index annual precipitation and reference evapotranspiration estimated using FAO-56 PenmanndashMonteith equation

Station name Precipitation (mmyear) PET (mmyear) Aridity index ClimateAksu 73947 97222 0076 AridAheqi 215045 98551 0218 SemiaridAlar 48910 102391 0048 Extreme aridBaicheng 119041 83252 0143 AridKeping 96343 110273 0087 AridKuche 69812 116473 0060 AridTurgat 246653 62134 0397 SemiaridWuqia 180106 108291 0166 AridKashi 67380 112591 0060 Arid

050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Prec

ipita

tion

(mm

)

AksuAheqiAlar

0

50

100

150

200

250

300

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

BaichengKepingKuche

050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

TurgatWuqiaKashi

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)

Figure 2 Annual precipitation time series at the 9 synoptic stations


005

115

225

335

4

Aksu

005

115

225

335

Aheqi

0

05

1

15

2

25

Alar

005

115

225

3

Baicheng

005

115

225

335

4

Keping

005

115

225

3

Kuche

005

115

225

335

Turgat

005

115

225

Wuqia

minus05minus1

minus15minus2

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 3 Continued


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2

Figure 3 Annual rainfall variability indices for the 9 synoptic stations

0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet

Figure 4 Distribution in percentage of dry normal and wet yearsfor the 9 synoptic stations during the period 1960ndash2010

precipitation time series If the time series are completelyrandom the autocorrelation function will be zero for all lagsother than zero In this study to accept the hypothesis 119867

0

1199031= 0 (that there is no correlation between two consecutive

observations and there is no persistence in the time series)the value of 119903

1should fall between minus02544 and 02544

Autocorrelation plot for the annual precipitation at the9 synoptic stations is presented in Figure 5 As shown theprecipitation had both positive and negative serial correla-tions The highest and at the same time the significant serialcorrelation of 0260 was obtained at the Baicheng stationwhile the lowest serial correlation of minus0104 was detected atthe Wuqia station

Lag-1 serial correlation coefficients for seasonal precipi-tation data at the observed stations during the period 1960ndash2010 are presented in Table 5 As shown a positive serialcorrelation was found in the spring summer autumn andwinter series at 778 889 667 and 778of the stationsrespectively The significant serial correlation was detectedin the autumn at Aheqi station Trends of precipitation areconsidered statistically at the 5 significance level using the

0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015

Figure 5 Lag-1 serial correlation coefficient for the precipitation atthe synoptic stations

Table 5 Lag-1 serial correlation coefficients for seasonal precipita-tion data

Station name Spring Summer Autumn WinterAksu 0102 0105 minus0042 0181Aheqi 0199 0009 0395 0102Alar minus0006 0147 minus0108 minus0078Baicheng 0192 0160 0140 0187Keping 0059 0167 0014 0113Kuche 0106 0035 minus0077 0077Turgat 0028 0019 0090 0163Wuqia minus0020 0100 0131 minus0068Kashi 0054 minus0050 0090 0019

MannndashKendall test and the Spearmanrsquos Rho test When asignificant trend is identified by two statistical methods thetrend is presented in bold character in Table 6

The results of the statistical tests for the monthly precip-itation series during the period 1960ndash2010 are summarizedin Table 6 As shown the precipitation in Baicheng stationhad the significant increasing trend in June and SeptemberThe significant increasing trend was also detected at the


0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)

Figure 6 Variations of monthly precipitation in stations with the significant trends during the study period

Kuche station in January June and December There wasno decreasing trend Besides A statistically significant trend119885119878= 2380 was detected in September at the Aheqi station

before eliminating the effect of serial correlation Afterremoving lag-1 serial correlation effect an insignificant trendof 119885119878= 1673 was obtained Furthermore an insignificant

trend 119885119863

= 1633 was detected in January at the Kuchestation before eliminating the effect of serial correlation Afterremoving lag-1 serial correlation effect a significant trend of119885119878= 2893 was obtainedSeasonal and annual trends of precipitation obtained

by statistical methods are given in Table 7 According tothese results the increasing trends in annual precipitationseries were detected at Aheqi Baicheng Keping and Kuchewhile there is no significant trend for other stations whichis consistent with our analysis in Section 31 On annuallevel precipitation quantities are increasing with the highestincrease in winter

For the seasonal scale there were increasing trendsin summer and winter precipitation series The decreasingprecipitation trendwas found in the spring and autumn seriesat 33 and 11 of the stations respectively Besides thesignificant increasing trends were found at Aheqi and Kashiin autumn and at Alar and Kuche in winter Furthermorethe significant increasing trends were detected at Baichengin summer autumn and winter The precipitation of Kepingalso had increasing trends in summer and autumn

35 Analysis of SPI-12 Time series of SPI-12 at the 9 synopticstations during the period 1960ndash2010 are shown in Figure 7Characteristics of drought at 12-month time scale are shownin Table 8 It should be observed that themost severe droughtof Aheqi and Alar was 1975 while that of Keping and Wuqiaoccurred in 1985 Besides the most severe drought year was1976 at Bacheng station and 1986 at Aksu station The Wuqiastation had the lowest SPI-12 with minus25986 in 1985 Thenumber of drought years during the observed period at thestations is presented in Table 8 According to the results thetotal drought years ranged between 14 (at Wuqia and Kashistation) and 19 (at Alar station) Almost 322 of the observedyears were drought years at all the 9 stations

Lag-1 serial correlation coefficient for the SPI-12 at theobserved synoptic stations is illustrated in Figure 8 Thehighest and at the same time the significant positive serialcorrelation coefficient of 02676 was detected at the Aksustation On the other hand negative values were observed atthe Turgat Wuqia and Kashi stations

The results of the MannndashKendall and Spearmanrsquos Rhotests for the SPI-12 series are presented in Figure 9 It canbe noted that all stations have the increasing trend Thesignificant trends were detected at Aheqi Baicheng Kepingand Kuche stations

Although a significantly increasing trend was detectedin the SPI-12 series of all the observed stations it can bedetermined that the western regions of Aksu River Basin have


0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

Figure 7 Time series of SPI-12 at the 9 synoptic stations

become much drier than the other parts during the period1960ndash2010 This had significant impact on agriculture andwater supply

4 Conclusions

Based on the analysis of the variation of precipitation anddrought indices and correlation in the multisites in this studyarea during 1960ndash2010 the following conclusions can bedrawn from this study

Precipitation trends and drought behavior at monthlyseasonal and annual time scale in Aksu River Basin between1960 and 2010 were investigated respectively In order toachieve this monthly seasonal and annual precipitationdata from 9 Serbian synoptic stations were analyzed usingthe MannndashKendall test and the Spearmanrsquos Rho test aftereliminating the effect of significant lag-1 serial correlationfrom the time series Besides aridity and annual rainfallvariability indices were estimated

According to these results two main annual droughtperiods were detected (1978-1979 and 1983ndash1986) while thedry year was 1975 and 1985 at almost all of the stationsThe monthly analysis of precipitation series suggests that allstations had increasing trend in July October andDecember

000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015

Figure 8 Lag-1 serial correlation coefficient for the SPI-12 at the 9synoptic stations

while both increasing and decreasing trends were found inother months At the seasonal scale there were increas-ing trends in summer and winter precipitation series Thedecreasing precipitation trend was found in the spring andautumn series at 33 and 11 of the stations respectively


Table 6 Results of the statistical tests for the monthly precipitation during the period 1960ndash2010

Station Test MonthJanuary February March April May June July August September October November December

Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863

0410 0884 0586 minus0279 0232 2014 0793 minus0890 1318 1203 0789 2060119887 0023 0060 0058 0016 0011 0184 0036 minus0075 0138 0122 minus0008 0038

Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863

0159 0319 0816 0615 0026 minus0146 1766 0524 1729 3249 1020 1250119887 0014 0019 0129 0019 0058 minus0054 0513 0236 0877 0227 minus0001 0024

Alar119885119878

1454 1175 minus0102 minus0171 0073 1276 1186 minus0016 minus0552 0026 0603 1523119885119863

1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747

119887 0025 0028 0023 minus0014 minus0050 0078 0106 0069 minus0067 0013 minus0003 0027

Baicheng119885119878

1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878

0311 1171 1308 minus0198 minus0073 0918 1706 1405 2278 1363 minus0249 0937119885119863

0525 1064 1665 minus0185 minus0026 0999 1849 1485 2447 1726 1112 1482119887 0045 0037 0102 0009 minus0014 0112 0273 0367 0284 0079 minus0012 0031

Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878

0033 minus0455 0723 0227 minus0382 1527 0796 0398 minus0106 2713 0122 2211

119885119863

minus0046 minus0428 0619 0254 minus0387 1498 0794 0392 minus0066 2810 0190 2307

119887 minus0003 minus0018 0019 0091 minus0058 0285 0164 0130 0023 0253 minus0006 0093

Wuqia119885119878

0708 minus1122 minus0228 minus0041 0195 1600 1787 minus0024 0699 2847 minus0016 1027119885119863

0699 minus1394 minus0375 minus0097 0007 1822 2194 minus0008 0677 2983 minus0151 1176119887 0032 minus0039 minus0048 0011 minus0092 0465 0407 minus0076 0141 0239 minus0015 0029

Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863

0685 minus0387 1758 minus0164 0401 1146 1327 0199 1294 3908 1071 1430119887 0048 minus0015 0106 minus0058 minus0115 0096 0111 minus0025 0104 0170 0024 0020

119885119878 MannndashKendall test 119885

119863 Spearmanrsquos Rho test and 119887 slope of linear regression

Bold characters represent trends identified by 2 statistical methods togetherStatistically significant trends at the 5 significance level

0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD

Figure 9 MannndashKendall test (119885119878

) and Spearmanrsquos Rho test (119885119863

) for the SPI-12 series


Table 7 Results of the statistical tests for seasonal and annual precipitation during the period 1960ndash2010

Station Test SeasonSpring Summer Autumn Winter Annual

Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863

minus0567 1793 minus0325 2152 1159119887 minus0041 0253 minus0057 0083 0235


0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466




Table 8 Characteristics of droughts at 12-month time scale

Station The most severe drought Number of drought years during the observed periodSPI Year Near normal Moderate Severeextreme Total

Aksu minus22748 1986 7 7 3 17Aheqi minus21138 1975 10 6 2 18Alar minus22262 1975 11 6 2 19Keping minus25112 1985 8 5 3 16Baicheng minus19470 1961 5 6 4 15Kuche minus18056 1965 8 6 4 18Turgat minus21432 1976 7 5 5 17Wuqia minus25986 1985 3 8 3 14Kashi minus19757 1994 6 3 5 14

For the SPI-12 all stations have the increasing trend Thesignificant trends were detected at Aheqi Baicheng Kepingand Kuche stations (As shown in Figure 6) Based on theanalysis of trends of precipitation and drought behaviorprecipitation in Aksu River Basin had an increasing trend

And drought condition including drought severity anddrought duration became better The analyzed results ofprecipitation and SPI-12 series can be helpful for basin-scale water resources management agricultural produc-tion Further research in analyzing the spatial variation of


precipitation trends and the relationship with the climatechange projection is recommended Moreover the futurework will be oriented into developing an information systemfor monitoring and early drought warning

Conflict of Interests

The authors declare that there is no conflict of interests

Authorsrsquo Contribution

Yuhu Zhang and Wanyuan Cai prepared the paper YuhuZhangQiuhuaChen andKaili Liumade the data processingYunjun Yao contributed to the discussion

Acknowledgments

The financial support of this work has been provided by theNational Science and Technology Support Plan during the12th Five-Year Plan Period of China projects (Grants nos2013BAC10B01 and 2012BAC19B03) and State Key Laboratoryof Desert and Oasis Ecology Xinjiang Institute of Ecologyand Geography Chinese Academy of Sciences downscalingcorrection model for satellite precipitation in mountainousarea of Xinjiang It is also realized as a part of the ProjectldquoStatistical Analysis and Information Extraction of High-Dimensional Complicate Datardquo jointly funded by ScientificResearch Project of Beijing Educational Committee (noKZ201410028030) The authors also would like to thankthe editors and the anonymous reviewers for their crucialcomments which will improve the quality of this paper

References

[1] H Hisdal K Stahl L M Tallaksen and S Demuth ldquoHavestreamflow droughts in Europe become more severe or fre-quentrdquo International Journal of Climatology vol 21 no 3 pp317ndash333 2001

[2] M Gocic and S Trajkovic ldquoAnalysis of precipitation anddrought data in Serbia over the period 1980ndash2010rdquo Journal ofHydrology vol 494 pp 32ndash42 2013

[3] M Gemmer S Becker and T Jiang ldquoObserved monthly pre-cipitation trends in China 1951ndash2002rdquo Theoretical and AppliedClimatology vol 77 no 1-2 pp 39ndash45 2004

[4] T Partal and E Kahya ldquoTrend analysis in Turkish precipitationdatardquoHydrological Processes vol 20 no 9 pp 2011ndash2026 2006

[5] Q Liu Z Yang and B Cui ldquoSpatial and temporal variability ofannual precipitation during 1961ndash2006 in Yellow River BasinChinardquo Journal of Hydrology vol 361 no 3-4 pp 330ndash3382008

[6] P G Oguntunde B J Abiodun and G Lischeid ldquoRainfalltrends in Nigeria 1901ndash2000rdquo Journal of Hydrology vol 411 no3-4 pp 207ndash218 2011

[7] H Tabari andPH Talaee ldquoTemporal variability of precipitationover Iran 1966ndash2005rdquo Journal ofHydrology vol 396 no 3-4 pp313ndash320 2011

[8] H Tabari H Abghari and P Hosseinzadeh Talaee ldquoTemporaltrends and spatial characteristics of drought and rainfall in aridand semiarid regions of IranrdquoHydrological Processes vol 26 no22 pp 3351ndash3361 2012

[9] E E Moreira C A Coelho A A Paulo L S Pereira and J TMexia ldquoSPI-based drought category prediction using loglinearmodelsrdquo Journal of Hydrology vol 354 no 1ndash4 pp 116ndash1302008

[10] A A Paulo and L S Pereira ldquoStochastic prediction of droughtclass transitionsrdquo Water Resources Management vol 22 no 9pp 1277ndash1296 2008

[11] S Shahid ldquoSpatial and temporal characteristics of droughts inthe western part of Bangladeshrdquo Hydrological Processes vol 22no 13 pp 2235ndash2247 2008

[12] D Khalili T Farnoud H Jamshidi A A Kamgar-Haghighiand S Zand-Parsa ldquoComparability analyses of the SPI andRDImeteorological drought indices in different climatic zonesrdquoWater Resources Management vol 25 no 6 pp 1737ndash1757 2011

[13] A K Mishra and V P Singh ldquoA review of drought conceptsrdquoJournal of Hydrology vol 391 no 1-2 pp 202ndash216 2010

[14] Y H Ding G Y Ren Z C Zhao et al ldquoDetection causes andprojection of climate change over China an overview of recentprogressrdquo Advances in Atmospheric Sciences vol 24 no 6 pp954ndash971 2007

[15] Y Shi Y Shen E Kang et al ldquoRecent and future climate changein northwest Chinardquo Climatic Change vol 80 no 3-4 pp 379ndash393 2007

[16] H Weng K-M Lau and Y Xue ldquoMulti-scale summer rainfallvariability over China and its long-term link to global seasurface temperature variabilityrdquo Journal of the MeteorologicalSociety of Japan vol 77 no 4 pp 845ndash857 1999

[17] C-P Chang Y Zhang and T Li ldquoInterannual and interdecadalvariations of the East Asian summer monsoon and tropicalpacific SSTs Part I Roles of the subtropical ridgerdquo Journal ofClimate vol 13 no 24 pp 4310ndash4325 2000

[18] G Ren H Wu and Z Chen ldquoSpatial patterns of change trendin rainfall of Chinardquo Quarterly Journal of Applied Meteorologyvol 11 pp 322ndash330 2000

[19] Y Ding Z Wang and Y Sun ldquoInter-decadal variation ofthe summer precipitation in east China and its associationwith decreasing Asian summer monsoon Part I observedevidencesrdquo International Journal of Climatology vol 28 no 9pp 1139ndash1161 2008

[20] Y Lei B Hoskins and J Slingo ldquoExploring the interplaybetween natural decadal variability and anthropogenic climatechange in summer rainfall over China Part I observationalevidencerdquo Journal of Climate vol 24 no 17 pp 4584ndash4599 2011

[21] R H Zhang B Y Wu P Zhao and J Han ldquoThe decadal shiftof the summer climate in the late 1980s over East China andits possible causesrdquo Acta Meteorological Sinica vol 66 pp 697ndash706 2008

[22] P Zhao Y Song and R C Yu ldquoLong-term changes in rainfallover Eastern China and large-scale atmospheric circulationassociated with recent global warmingrdquo Journal of Climate vol23 no 6 pp 1544ndash1562 2010

[23] D Yihui R Guoyu S Guangyu et al ldquoChinarsquos national assess-ment report on climate change (I) climate change in China andthe future trendrdquo Advances in Climate Change Research vol 3supplement pp 1ndash5 2007

[24] K E Trenberth and P D Jones ldquoObservations surface andatmospheric climate changerdquo in Climate Change 2007 ThePhysical Science Basis S Solomon D Qin M Manning etal Eds chapter 3 pp 235ndash336 Cambridge University PressCambridge UK 2007


[25] H Ye and R Lu ldquoSubseasonal variation in ENSO-relatedeast asian rainfall anomalies during summer and its role inweakening the relationship between the ENSO and summerrainfall in eastern china since the late 1970srdquo Journal of Climatevol 24 no 9 pp 2271ndash2284 2011

[26] A Duan M Wang Y Lei and Y Cui ldquoTrends in summerrainfall over china associated with the Tibetan Plateau sensibleheat source during 1980ndash2008rdquo Journal of Climate vol 26 no1 pp 261ndash275 2013

[27] Z Zhu T Li and J He ldquoOut-of-phase relationship betweenBoreal spring and summer decadal rainfall changes in SouthernChinardquo Journal of Climate vol 27 no 3 pp 1083ndash1099 2014

[28] Y N Chen and Z X Xu ldquoPlausible impact of global climatechange on water resources in the Tarim River Basinrdquo Science inChina Series D Earth Sciences vol 48 no 1 pp 65ndash73 2005

[29] H Li Z Jiang and Q Yang ldquoAssociation of north atlantic oscil-lations with aksu river runoff in Chinardquo Journal of GeographicalSciences vol 19 no 1 pp 12ndash24 2009

[30] S Zhang S Liu XMo C Shu Y Sun and C Zhang ldquoAssessingthe impact of climate change on reference evapotranspiration inAksu River Basinrdquo Acta Geographica Sinica vol 65 no 11 pp1363ndash1370 2010

[31] S Zhang S Liu XMo C Shu Y Sun and C Zhang ldquoAssessingthe impact of climate change on potential evapotranspiration inAksu River Basinrdquo Journal of Geographical Sciences vol 21 no4 pp 609ndash620 2011

[32] B Li Y Chen X Shi Z Chen andW Li ldquoTemperature and pre-cipitation changes in different environments in the arid regionof northwest Chinardquo Theoretical and Applied Climatology vol112 no 3-4 pp 589ndash596 2013

[33] HWang Y Chen S Xun D Lai Y Fan and Z Li ldquoChanges indaily climate extremes in the arid area of northwestern ChinardquoTheoretical and Applied Climatology vol 112 no 1-2 pp 15ndash282013

[34] S Han and H Hu ldquoSpatial variations and temporal changesin potential evaporation in the Tarim Basin Northwest China(1960ndash2006) influenced by irrigationrdquo Hydrological Processesvol 26 no 20 pp 3041ndash3051 2012

[35] Q Zhang J Li V P Singh and Y Bai ldquoSPI-based evaluationof drought events in Xinjiang ChinardquoNatural Hazards vol 64no 1 pp 481ndash492 2012

[36] Y N Chen K Takeuchi C Xu Y P Chen and Z X XuldquoRegional climate change and its effects on river runoff in theTarim Basin Chinardquo Hydrological Processes vol 20 no 10 pp2207ndash2216 2006

[37] Y-N Chen W-H Li C-C Xu and X-M Hao ldquoEffectsof climate change on water resources in Tarim River BasinNorthwest Chinardquo Journal of Environmental Sciences vol 19 no4 pp 488ndash493 2007

[38] C Yaning X Changchun H Xingming et al ldquoFifty-yearclimate change and its effect on annual runoff in the TarimRiverBasin Chinardquo Quaternary International vol 208 no 1-2 pp53ndash61 2009

[39] H F Lee and D D Zhang ldquoRelationship between NAO anddrought disasters in northwestern China in the last millen-niumrdquo Journal of Arid Environments vol 75 no 11 pp 1114ndash1120 2011

[40] H Ling H Xu and J Fu ldquoChanges in intra-annual runoffand its response to climate change and human activities in theheadstream areas of the Tarim River Basin Chinardquo QuaternaryInternational vol 336 no 26 pp 158ndash170 2014

[41] R Ouyang W Cheng W Wang Y Jiang Y Zhang and YWang ldquoResearch on runoff forecast approaches to the AksuRiver basinrdquo Science in China Series D Earth Sciences vol 50no 1 supplement pp 16ndash25 2007

[42] X L Wang ldquoComment on lsquodetection of undocumented changepoint a revision of the two-phase regression modelrsquordquo Journal ofClimate vol 16 no 20 pp 3383ndash3385 2003

[43] World Meteorological Organization (WMO) Drought andAgricultureWMOTN 138WorldMeteorologicalOrganization(WMO) Geneva Switzerland 1975

[44] United Nations Environmental Programme (UNEP) WorldAtlas of Desertification United Nations Environmental Pro-gramme (UNEP) 1992

[45] R G AllenM E Jensen J LWright andRD Burman ldquoOper-ational estimates of reference evapotranspirationrdquo AgronomyJournal vol 81 no 4 pp 650ndash662 1989

[46] R G Allen L S Pereira D Raes and M Smith ldquoCrop evap-otranspiration Guidelines for computing crop water require-mentsrdquo FAO Irrigation and Drainage Paper 56 Food andAgriculture Organization of the United Nation Rome Italy1998

[47] M Bannayan S Sanjani A Alizadeh S S Lotfabadi andA Mohamadian ldquoAssociation between climate indices aridityindex and rainfed crop yield in Northeast of Iranrdquo Field CropsResearch vol 118 no 2 pp 105ndash114 2010

[48] R R Heim Jr ldquoA review of twentieth-century drought indicesused in the United Statesrdquo Bulletin of the American Meteorolog-ical Society vol 83 no 8 pp 1149ndash1165 2002

[49] M V K Sivakumar R P Motha D A Wilhite and D AWood Agricultural Drought Indices Proceedings of an ExpertMeeting 2ndash4 June 2010 Murcia Spain World MeteorologicalOrganization Geneva Switzerland 2010

[50] T B McKee N J Doesken and J Kleist ldquoThe relationship ofdrought frequency and duration to time scalesrdquo in Proceedingsof the 8th Conference on Applied Climatology pp 179ndash184Anaheim Calif USA January 1993

[51] T B McKee N J Doesken and J Kleist ldquoDrought monitoringwith multiple time scalesrdquo in Proceedings of the 9th Conferenceon Applied Climatology pp 233ndash236 American MeteorologicalSociety Boston Mass USA January 1995

[52] K E Logan N A Brunsell A R Jones and J J FeddemaldquoAssessing spatiotemporal variability of drought in the UScentral plainsrdquo Journal of Arid Environments vol 74 no 2 pp247ndash255 2010

[53] M J Hayes M D Svoboda D AWilhite andO V VanyarkholdquoMonitoring the 1996 drought using the standardized precipita-tion indexrdquo Bulletin of the American Meteorological Society vol80 no 3 pp 429ndash438 1999

[54] R A Seiler M Hayes and L Bressan ldquoUsing the standardizedprecipitation index for flood risk monitoringrdquo InternationalJournal of Climatology vol 22 no 11 pp 1365ndash1376 2002

[55] H C S Thom ldquoA note on the gamma distributionrdquo MonthlyWeather Review vol 86 no 4 pp 117ndash122 1958

[56] H C S Thom ldquoSome methods of climatological analysisrdquoWMO Technical Note 81 Secretariat of the World Meteorolog-ical Organization Geneva Switzerland 1966

[57] D C Edwards andT BMcKee ldquoCharacteristics of 20th centurydrought in the United States at multiple scalesrdquo AtmosphericScience Paper 634 1997

[58] M Abramowitz and I A Stegun Handbook of MathematicalFunctions Dover Publications New York NY USA 1965


[59] I Bordi S Frigio P Parenti A Speranza and A SuteraldquoThe analysis of the Standardized Precipitation Index in theMediterranean area large-scale patternsrdquo Annals of Geophysicsvol 44 no 5-6 pp 965ndash978 2001

[60] B Lloyd-Hughes and M A Saunders ldquoA drought climatologyfor Europerdquo International Journal of Climatology vol 22 no 13pp 1571ndash1592 2002

[61] B Bonaccorso I Bordi A Cancelliere G Rossi and A SuteraldquoSpatial variability of drought an analysis of the SPI in SicilyrdquoWater Resources Management vol 17 no 4 pp 273ndash296 2003

[62] T Raziei B Saghafian A A Paulo L S Pereira and I BordildquoSpatial patterns and temporal variability of drought inWesternIranrdquoWater Resources Management vol 23 no 3 pp 439ndash4552009

[63] M Gocic and S Trajkovic ldquoAnalysis of changes in meteoro-logical variables using Mann-Kendall and Senrsquos slope estimatorstatistical tests in SerbiardquoGlobal and Planetary Change vol 100pp 172ndash182 2013

[64] M A Kohler ldquoDouble-mass analysis for testing the consistencyof records and formaking adjustmentsrdquoBulletin of theAmericanMeteorological Society vol 30 pp 188ndash189 1949

[65] T Niedzwiedz R Twardosz and A Walanus ldquoLong-term vari-ability of precipitation series in east central Europe in relation tocirculation patternsrdquo Theoretical and Applied Climatology vol98 no 3-4 pp 337ndash350 2009

[66] A A Paulo R D Rosa and L S Pereira ldquoClimate trendsand behaviour of drought indices based on precipitation andevapotranspiration in Portugalrdquo Natural Hazards and EarthSystem Science vol 12 no 5 pp 1481ndash1491 2012

[67] J D Ruiz Sinoga R Garcia Marin J F Martinez Murillo andM A Gabarron Galeote ldquoPrecipitation dynamics in southernSpain trends and cyclesrdquo International Journal of Climatologyvol 31 no 15 pp 2281ndash2289 2011

[68] M Unkasevic and I Tosic ldquoA statistical analysis of the dailyprecipitation over Serbia trends and indicesrdquo Theoretical andApplied Climatology vol 106 no 1-2 pp 69ndash78 2011

[69] H BMann ldquoNonparametric tests against trendrdquo Econometricavol 13 pp 245ndash259 1945

[70] M G Kendall Rank CorrelationMethods Griffin London UK1975

[71] E L Lehmann Nonparametrics Statistical Methods Based onRanks HoldenDay San Francisco Calif USA 1975

[72] R Sneyers ldquoOn the statistical analysis of series of observationsrdquoTechnical Note no 143 World Meteorological OrganizationGeneva Switzerland 1990

[73] H von Storch and A Navarra Analysis of Climate VariabilitymdashApplications of Statistical Techniques Springer New York NYUSA 1995

[74] J D Salas J W Delleur V M Yevjevich and W L LaneApplied Modeling of Hydrologic Time Series Water ResourcesPublications Littleton Colo USA 1980

[75] M G Kendall and A StuartThe Advanced Theory of StatisticsDesign and Analysis and Time-Series vol 3 Charles Griffin ampCompany Limited London UK 1968

[76] M Gocic and S Trajkovic ldquoSoftware for estimating referenceevapotranspiration using limited weather datardquo Computers andElectronics in Agriculture vol 71 no 2 pp 158ndash162 2010

[77] MGocic and S Trajkovic ldquoService-oriented approach formod-eling and estimating reference evapotranspirationrdquo Computersand Electronics in Agriculture vol 79 no 2 pp 153ndash158 2011

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Geology Advances in


the increasing precipitation in spring but slightly decreasingin autumn in the last decades [23] and the frequency of heavyprecipitation events increased in China [24] Mechanismshave also been proposed to explain precipitation changes [25ndash27] Affected by decadal changes of the global climate sys-tem precipitation in China is characterized with significantdecadal changes especially since the 1990s and the increasedglobal warming plus the reenhanced East Asianmonsoon arebound to influence the regional precipitation distribution andits changing trend Precipitation changes might greatly affectregional climate stability hydrological processes and wateravailability

Furthermore there have been a number of drought andprecipitation studies for different periods in Aksu RiverBasin Related studies [28ndash35] have indicated that thereis a change about precipitation and drought indices Forexample Chen et al [36] summarized that the streamflowfrom the headwaters of the Tarim River shows significantincrease and is sensitive to precipitation but the streamflowalong the mainstream of the river has decreased Chenet al [37 38] analyzed the fifty-year climate change and itseffect on annual runoff at Aksu River Basin The streamflowshowed a significant increasing monotonic trendThe annualrunoff in the Aksu River had increased by 109 since 1990They also detected the long-term trends of the hydrolog-ical time series using both parametric and nonparametrictechniques based on temperature and precipitation datafrom the past 50 years The temperature the precipitationand the streamflow from the headwater of the Tarim Riverexhibited a significant increase during the last 20 years Leeand Zhang [39] further developed the relationship betweenNAOand drought disasters in northwesternChina Statisticalresults show that NAO and drought disaster were negativelycorrelated as positive modes of NAO caused northward-displaced stronger-than-average midlatitudeWesterlies withan enhanced latitudinal water vapor gradient into the centralAsian drylands resulting in reduced drought frequency andintensity in northwestern China Ling et al [40] investigatedintra-annual runoff trends and periods in the headstreamareas of the Tarim River Basin by nonparametric tests andwavelet analysis The results showed that the runoff airtemperature and precipitation of the headstreams increasedremarkably during both high-flow and low-flow periods

However most of the previous work on a comprehensiveanalysis of trends and variability using statistical test anddrought indices in precipitation series over Aksu River Basinis still lacking Thus it is necessary to analyze the trend ofprecipitation and characteristics of drought to explore thecauses and the formation mechanism of Aksu River Basindrought which is vital for drought forecast defense andmitigation The analysis of drought variability can improvewater resources management in the area

The main goals of the study were to study variability ofprecipitation on monthly seasonal and annual time scalethrough applying the linear regression MannndashKendall andSpearmanrsquos Rho methods to assess precipitation predictionfor the Aksu River Basin in China and to analyze the impactof serial correlation in detecting trends and to investigate thedrought in study area from 1960 to 2010

2 Materials and Methods

21 Study Area and Database The Aksu River Basin (75∘35ndash82∘001015840E 40∘17ndash42∘271015840N) is located in the western part ofthe middle southern slope of the Tianshan Mountains andat the northwestern edge of the Tarim Basin The totalarea is 514 times 104 km2 of which the area of the regionin China is 31 times 104 km2 The basin is in the interior ofthe Eurasian continent Vast territory diverse topographycomplex terrain and typical regional climate variationsmadeup the characteristics of the northwest mountain climateIt has lower temperatures plentiful precipitation and agedsnow in the high mountain zone while the middle mountainzone brings about changes in temperature clearly and isthe largest precipitation distribution area The low mountainzone suffers from drought large temperature changes and isfairly well in heat conditions Due to the Taklimakan Desertin the south and the Tianshan Mountains in the north thecool air and vapor derived from Central Asia Siberia andArctic Ocean do not straightly enter into the southeasternplain region which causes typical temperate continental dryclimate regional characteristics such as minimal precipita-tion intense evaporation adequate sunshine and extremeheat [41]

Daily precipitation saturation vapor pressure net radia-tion soil heat flux density temperature average 24 h windspeed at 2m height and vapor pressure data were collectedfrom 9 meteorological stations distributed in study area(shown in Figure 1) for the period 1961ndash2010 and wereobtained from meteorological data shared in service systemof China (httpdatacmagovcn) Seasons were defined asfollows winter = December January and February spring =March April and May summer = June July and Augustand autumn = September October and November Thegeographical location of the selected meteorological stationsis presented in Table 1

The precipitation datasets were investigated for homo-geneity and absence of trends The autocorrelation analysiswas applied to the monthly precipitation time series of eachstation The precipitation data were quality controlled (QC)from [42]

22 Rainfall Variability Index (RVI) RVI (120575) is calculated asfollows

120575119894=

(119875119894minus 120583)

120590

(1)

where 120575119894= Rainfall Variability Index for year 119894 119875

119894= annual

rainfall for year 119894 and 120583 and 120590 are the mean annual rainfalland standard deviation for the period of the year 1961ndash2010A drought year occurs if the 120575 is negative

According to WMO [43] rainfall time series can beclassified into different climatic regimes

extreme dry 119875 lt 120583 minus 2 sdot 120590

dry 120583 minus 2 sdot 120590 lt 119875 lt 120583 minus 120590

normal 120583 minus 120590 lt 119875 lt 120583 + 120590

wet 119875 gt 120583 + 120590

(2)



Kyrgyzstan

NEW

S


DEM

Low 173High 8354

Kashi

Baicheng

KepingAheqi

AlarAksu

Kuche

WuqiaTurgat


(km)0 75 150 300

46∘N

44∘N

42∘N

40∘N

38∘N

46∘N

44∘N

42∘N

40∘N

38∘N

75∘E

75∘E

80∘E

80∘E





PET =


2sdot VPD

Δ + 120574 sdot (1 + 034 sdot 1198802)

(3)











119892 (119909) =

1

120573120572

sdot Γ (120572)

119909120572minus1

sdot 119890minus119909120573

119909 gt 0 (4)


Γ (120572) = int

infin

0

119910120572minus1

119890minus119910

119889119910 (5)



120572pro =

1

4119860

(1 + radic1 +

4119860

3

)

119860 = ln (119909sr) minussum119899

119894=1

ln (119909119894)

119899

120573pro =

119909sr120572pro

(6)





119866 (119909) = int

119909

0

119892 (119909) 119889119909 =

1

120573

119909propro Γ (120572pro)

int

119909

0

119909120572prominus1

119890minus119909120573pro

119889119909

(7)


119867(119909) = 119902 + (1 minus 119902)119866 (119909) (8)


119902 =

119898

119899

(9)



SPI =

minus(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 0 lt 119867 (119909) le 05

+(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 05 lt 119867 (119909) le 10

(10)


119905 =

radicln 1

(119867 (119909))2

0 lt 119867 (119909) le 05

radicln 1

(1 minus 119867 (119909))2

05 lt 119867 (119909) le 10

(11)

And 1198880 1198881 1198882 1198891 1198892 and 119889


are [58ndash60]1198880= 2515517 119888

1= 0802853 119888

2= 0010328

1198891= 1432788 119889

2= 0189269 119889

3= 0001308

(12)







119878 =

119899minus1

sum

119894=1

119899

sum

119895=119894+1

sgn (119909119895minus 119909119894) (13)


119895are the data



sgn (119909119895minus 119909119894) =

+1 if 119909119895minus 119909119894gt 0

0 if 119909119895minus 119909119894= 0

minus1 if 119909119895minus 119909119894lt 0

(14)


120583 (119878) = 0

1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5) minus sum119898

119894=1

119905119894(119905119894minus 1) (2119905

119894+ 5)

18

(15)





1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5)

18

(16)


119885119878=

119878 minus 1

radic1205902

(119878)

if 119878 gt 0

0 if 119878 = 0

119878 + 1

radic1205902

(119878)

if 119878 lt 0

(17)




119878| gt 196


119863


119863 = 1 minus

6sum119899

119894=1

(119877 (119883119894) minus 119894)2

119899 (1198992

minus 1)

119885119863= 119863radic

119899 minus 2

1 minus 1198632

(18)


119895in the time








1199031=

(1 (119899 minus 1))sum119899minus1

119894=1

(119909119894minus 120583 (119909

119894)) sdot (119909

119894+1minus 120583 (119909

119894))

(1119899)sum119899

119894=1

(119909119894minus 120583 (119909

119894))2

120583 (119909119894) =

1

119899

119899

sum

119894=1

119909119894

(19)




by

1199031(005) =


119899 minus 1

(20)















050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Prec

ipita

tion

(mm

)

AksuAheqiAlar

0

50

100

150

200

250

300

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

BaichengKepingKuche

050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

TurgatWuqiaKashi

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)



005

115

225

335

4

Aksu

005

115

225

335

Aheqi

0

05

1

15

2

25

Alar

005

115

225

3

Baicheng

005

115

225

335

4

Keping

005

115

225

3

Kuche

005

115

225

335

Turgat

005

115

225

Wuqia

minus05minus1

minus15minus2

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 3 Continued


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2


0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet



0






0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015







0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in



Kyrgyzstan

NEW

S


DEM

Low 173High 8354

Kashi

Baicheng

KepingAheqi

AlarAksu

Kuche

WuqiaTurgat


(km)0 75 150 300

46∘N

44∘N

42∘N

40∘N

38∘N

46∘N

44∘N

42∘N

40∘N

38∘N

75∘E

75∘E

80∘E

80∘E





PET =


2sdot VPD

Δ + 120574 sdot (1 + 034 sdot 1198802)

(3)











119892 (119909) =

1

120573120572

sdot Γ (120572)

119909120572minus1

sdot 119890minus119909120573

119909 gt 0 (4)


Γ (120572) = int

infin

0

119910120572minus1

119890minus119910

119889119910 (5)



120572pro =

1

4119860

(1 + radic1 +

4119860

3

)

119860 = ln (119909sr) minussum119899

119894=1

ln (119909119894)

119899

120573pro =

119909sr120572pro

(6)





119866 (119909) = int

119909

0

119892 (119909) 119889119909 =

1

120573

119909propro Γ (120572pro)

int

119909

0

119909120572prominus1

119890minus119909120573pro

119889119909

(7)


119867(119909) = 119902 + (1 minus 119902)119866 (119909) (8)


119902 =

119898

119899

(9)



SPI =

minus(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 0 lt 119867 (119909) le 05

+(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 05 lt 119867 (119909) le 10

(10)


119905 =

radicln 1

(119867 (119909))2

0 lt 119867 (119909) le 05

radicln 1

(1 minus 119867 (119909))2

05 lt 119867 (119909) le 10

(11)

And 1198880 1198881 1198882 1198891 1198892 and 119889


are [58ndash60]1198880= 2515517 119888

1= 0802853 119888

2= 0010328

1198891= 1432788 119889

2= 0189269 119889

3= 0001308

(12)







119878 =

119899minus1

sum

119894=1

119899

sum

119895=119894+1

sgn (119909119895minus 119909119894) (13)


119895are the data



sgn (119909119895minus 119909119894) =

+1 if 119909119895minus 119909119894gt 0

0 if 119909119895minus 119909119894= 0

minus1 if 119909119895minus 119909119894lt 0

(14)


120583 (119878) = 0

1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5) minus sum119898

119894=1

119905119894(119905119894minus 1) (2119905

119894+ 5)

18

(15)





1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5)

18

(16)


119885119878=

119878 minus 1

radic1205902

(119878)

if 119878 gt 0

0 if 119878 = 0

119878 + 1

radic1205902

(119878)

if 119878 lt 0

(17)




119878| gt 196


119863


119863 = 1 minus

6sum119899

119894=1

(119877 (119883119894) minus 119894)2

119899 (1198992

minus 1)

119885119863= 119863radic

119899 minus 2

1 minus 1198632

(18)


119895in the time








1199031=

(1 (119899 minus 1))sum119899minus1

119894=1

(119909119894minus 120583 (119909

119894)) sdot (119909

119894+1minus 120583 (119909

119894))

(1119899)sum119899

119894=1

(119909119894minus 120583 (119909

119894))2

120583 (119909119894) =

1

119899

119899

sum

119894=1

119909119894

(19)




by

1199031(005) =


119899 minus 1

(20)















050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Prec

ipita

tion

(mm

)

AksuAheqiAlar

0

50

100

150

200

250

300

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

BaichengKepingKuche

050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

TurgatWuqiaKashi

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)



005

115

225

335

4

Aksu

005

115

225

335

Aheqi

0

05

1

15

2

25

Alar

005

115

225

3

Baicheng

005

115

225

335

4

Keping

005

115

225

3

Kuche

005

115

225

335

Turgat

005

115

225

Wuqia

minus05minus1

minus15minus2

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 3 Continued


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2


0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet



0






0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015







0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in



120572pro =

1

4119860

(1 + radic1 +

4119860

3

)

119860 = ln (119909sr) minussum119899

119894=1

ln (119909119894)

119899

120573pro =

119909sr120572pro

(6)





119866 (119909) = int

119909

0

119892 (119909) 119889119909 =

1

120573

119909propro Γ (120572pro)

int

119909

0

119909120572prominus1

119890minus119909120573pro

119889119909

(7)


119867(119909) = 119902 + (1 minus 119902)119866 (119909) (8)


119902 =

119898

119899

(9)



SPI =

minus(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 0 lt 119867 (119909) le 05

+(119905 minus

1198880+ 1198881119905 + 11988821199052

1 + 1198891119905 + 11988921199052

+ 11988931199053

) 05 lt 119867 (119909) le 10

(10)


119905 =

radicln 1

(119867 (119909))2

0 lt 119867 (119909) le 05

radicln 1

(1 minus 119867 (119909))2

05 lt 119867 (119909) le 10

(11)

And 1198880 1198881 1198882 1198891 1198892 and 119889


are [58ndash60]1198880= 2515517 119888

1= 0802853 119888

2= 0010328

1198891= 1432788 119889

2= 0189269 119889

3= 0001308

(12)







119878 =

119899minus1

sum

119894=1

119899

sum

119895=119894+1

sgn (119909119895minus 119909119894) (13)


119895are the data



sgn (119909119895minus 119909119894) =

+1 if 119909119895minus 119909119894gt 0

0 if 119909119895minus 119909119894= 0

minus1 if 119909119895minus 119909119894lt 0

(14)


120583 (119878) = 0

1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5) minus sum119898

119894=1

119905119894(119905119894minus 1) (2119905

119894+ 5)

18

(15)





1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5)

18

(16)


119885119878=

119878 minus 1

radic1205902

(119878)

if 119878 gt 0

0 if 119878 = 0

119878 + 1

radic1205902

(119878)

if 119878 lt 0

(17)




119878| gt 196


119863


119863 = 1 minus

6sum119899

119894=1

(119877 (119883119894) minus 119894)2

119899 (1198992

minus 1)

119885119863= 119863radic

119899 minus 2

1 minus 1198632

(18)


119895in the time








1199031=

(1 (119899 minus 1))sum119899minus1

119894=1

(119909119894minus 120583 (119909

119894)) sdot (119909

119894+1minus 120583 (119909

119894))

(1119899)sum119899

119894=1

(119909119894minus 120583 (119909

119894))2

120583 (119909119894) =

1

119899

119899

sum

119894=1

119909119894

(19)




by

1199031(005) =


119899 minus 1

(20)















050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Prec

ipita

tion

(mm

)

AksuAheqiAlar

0

50

100

150

200

250

300

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

BaichengKepingKuche

050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

TurgatWuqiaKashi

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)



005

115

225

335

4

Aksu

005

115

225

335

Aheqi

0

05

1

15

2

25

Alar

005

115

225

3

Baicheng

005

115

225

335

4

Keping

005

115

225

3

Kuche

005

115

225

335

Turgat

005

115

225

Wuqia

minus05minus1

minus15minus2

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 3 Continued


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2


0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet



0






0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015







0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in



1205902

(119878) =

119899 (119899 minus 1) (2119899 + 5)

18

(16)


119885119878=

119878 minus 1

radic1205902

(119878)

if 119878 gt 0

0 if 119878 = 0

119878 + 1

radic1205902

(119878)

if 119878 lt 0

(17)




119878| gt 196


119863


119863 = 1 minus

6sum119899

119894=1

(119877 (119883119894) minus 119894)2

119899 (1198992

minus 1)

119885119863= 119863radic

119899 minus 2

1 minus 1198632

(18)


119895in the time








1199031=

(1 (119899 minus 1))sum119899minus1

119894=1

(119909119894minus 120583 (119909

119894)) sdot (119909

119894+1minus 120583 (119909

119894))

(1119899)sum119899

119894=1

(119909119894minus 120583 (119909

119894))2

120583 (119909119894) =

1

119899

119899

sum

119894=1

119909119894

(19)




by

1199031(005) =


119899 minus 1

(20)















050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Prec

ipita

tion

(mm

)

AksuAheqiAlar

0

50

100

150

200

250

300

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

BaichengKepingKuche

050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

TurgatWuqiaKashi

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)



005

115

225

335

4

Aksu

005

115

225

335

Aheqi

0

05

1

15

2

25

Alar

005

115

225

3

Baicheng

005

115

225

335

4

Keping

005

115

225

3

Kuche

005

115

225

335

Turgat

005

115

225

Wuqia

minus05minus1

minus15minus2

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 3 Continued


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2


0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet



0






0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015







0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in






050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Prec

ipita

tion

(mm

)

AksuAheqiAlar

0

50

100

150

200

250

300

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

BaichengKepingKuche

050

100150200250300350400450

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

TurgatWuqiaKashi

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)



005

115

225

335

4

Aksu

005

115

225

335

Aheqi

0

05

1

15

2

25

Alar

005

115

225

3

Baicheng

005

115

225

335

4

Keping

005

115

225

3

Kuche

005

115

225

335

Turgat

005

115

225

Wuqia

minus05minus1

minus15minus2

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 3 Continued


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2


0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet



0






0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015







0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in


005

115

225

335

4

Aksu

005

115

225

335

Aheqi

0

05

1

15

2

25

Alar

005

115

225

3

Baicheng

005

115

225

335

4

Keping

005

115

225

3

Kuche

005

115

225

335

Turgat

005

115

225

Wuqia

minus05minus1

minus15minus2

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

RVI(120575)

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus25

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

minus05

minus1

minus15

minus2

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 3 Continued


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2


0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet



0






0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015







0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in


005

115

225

335

4

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Kashi

RVI(120575)

minus05

minus1

minus15

minus2


0001020304050607080910

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Prob

abili

ty

Stations

DryNormalWet



0






0005

01015

02025

03

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

minus005

minus01minus015







0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in


0

5

10

15

20

25

30

35

Aksu

October month

0

5

10

15

20

25

30

35

40

Aheqi

October month

0

5

10

15

20

Prec

ipita

tion

(mm

)

Alar

December month

0

10

20

30

40

50

60

70

Keping

September month

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20101960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

y = 01227x minus 23986

R2 = 00677

y = 0227x minus 44389

R2 = 01527

y = 00273x minus 53335

R2 = 00268

y = 02842x minus 55523

R2 = 014Pr

ecip

itatio

n (m

m)

Prec

ipita

tion

(mm

)

Prec

ipita

tion

(mm

)




trend 119885119863









0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in


0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

0

1

2

3

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

SPI-

12

AksuAheqiAlar

BaichengKepingKuche

TurgatWuqiaKashi

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3

SPI-

12

minus1

minus2

minus3



4 Conclusions




000005010015020025030

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Lag-

1 se

rial

corr

elat

ion

coeffi

cien

t

minus005

minus010

minus015






Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in




Aksu119885119878

0233 0760 0411 minus0579 0276 1755 0796 minus0926 1365 0976 0000 1588119885119863


Aheqi119885119878

0139 0383 0789 0545 0016 minus0244 1576 0390 1673 2795 0798 1088119885119863


Alar119885119878


1964 2166 0658 0494 minus0025 1439 1309 0021 minus0399 0521 2088 2747



1206 1007 0253 0262 1089 2193 1901 1324 2161 1322 0886 1605119885119863

1394 0786 0247 0339 1155 2477 1926 1175 2207 1339 1313 1783119887 0042 0083 0037 minus0025 0077 0268 0234 0122 0228 0231 0089 0042

Keping119885119878



Kuche119885119878

2633 0919 minus0694 0679 0699 2437 0999 1357 0553 0513 1896 2533

119885119863

2893 1024 minus0541 0773 0808 2747 1057 1279 0476 0651 2626 3113

119887 0048 0052 minus0036 0023 0106 0207 0061 0063 0019 0013 minus0010 0039

Turgat119885119878


119885119863



Wuqia119885119878



Kashi119885119878

0507 minus0638 1455 minus0156 0602 0999 1406 0268 1223 3249 0365 1035119885119863





0

05

1

15

2

25

3

35

0

05

1

15

2

25

3

35

4

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Aks

u

Ahe

qi

Ala

r

Baic

heng

Kepi

ng

Kuch

e

Turg

at

Wuq

ia

Kash

i

Stations

Zs

ZD







Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in




Aksu119885119878

0341 0780 1673 1154 1495119885119863

0295 0952 1696 1264 1690119887 0084 0145 0253 0125 0603

Aheqi119885119878

0309 1056 2209 0739 2819

119885119863

0434 1106 2338 0529 3026

119887 0206 0695 1103 0055 2062

Alar119885119878

minus0520 1592 minus0390 1947 1129119885119863



0390 2713 2266 2112 2193

119885119863

0392 3029 2444 2214 2620

119887 0089 0624 0548 0166 1427

Keping119885119878

0244 2372 2429 1357 2875

119885119863

0404 2567 2552 1483 3300

119887 0097 0752 0351 0113 1313

Kuche119885119878

0430 1852 0423 2145 2494

119885119863

0416 2050 0263 2274 2743

119887 0093 0331 0023 0141 0585

Turgat119885119878

0195 1503 1194 1803 1527119885119863

0283 1379 1225 1874 1667119887 0052 0579 0270 0099 0973

Wuqia119885119878

minus0260 1462 1698 0065 1251119885119863

minus0342 1599 1579 0062 1281119887 minus0129 0796 0365 0014 1054

Kashi119885119878

minus0195 1121 2527 0390 1129119885119863

minus0223 1150 2547 0499 1055119887 minus0067 0182 0297 0041 0466















Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in







Acknowledgments


References

























































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in

































































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in

research article analysis of changes in precipitation and...

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