Performance assessment of irrigation water managementin old lands of the Nile delta of Egypt

Doaa E. El-Agha & David J. Molden &

Ashraf M. Ghanem

Published online: 24 November 2011# Springer Science+Business Media B.V. 2011

Abstract This paper provides the methodology and results of a cross-scale diagnosticperformance assessment program of the irrigation water management in the old lands of theNile Delta of Egypt. The analysis was done at three levels; main canal level, branch canalslevel and on-farm level of the Meet Yazid command (82,740 ha) for the year 2008–2009 tohighlight areas for improvement. At the main canal level the annual average percentage ofirrigation water returning to drains and groundwater was 53% of the total water supplied.Since Meet Yazid lies at tail end of the delta, and there is groundwater salinity,opportunities for reuse are increasingly limited moving north to Lake Burullus. This wouldindicate opportunities for real water savings. The results of monthly relative water supply ofthe main canal indicated mismatch between demand and supply especially during the wintermonths, and when supply is low farmers do reuse drainage or groundwater. Also, theassessment of the three branch canals showed non-uniformity of water distribution andmismatch between demand and supply even when comparing improved and non-improvedcanals. At the on-farm level in paddy fields, the amount of irrigation flows to drains andsaline sinks varied from 0.46 to 0.71 of inflow. In spite of these values of non-uniformityand low depleted fraction, the relative evapotranspiration (ratio of actual to potential)evaporation was uniformly high, indicating most crops of most farmers were not waterstressed, which is also confirmed by the high yield values. The average values ofproductivity per unit water depleted by ETact were 1.04 and 1.05 kg/m3 for rice and wheatfields, respectively, with yields of rice and wheat at 8 and 6 t per ha respectively. On farmand tertiary improvements alone will not yield real water savings, as excess water in themain canal and drains will continue to flow out of the system. Rather the focus should firstbe on supplies to the main canal, accompanied by more precise on farm and water delivery

Irrig Drainage Syst (2011) 25:215–236DOI 10.1007/s10795-011-9116-z

D. E. El-Agha (*)Ministry of Water Resources and Irrigation, Giza, Egypte-mail: doaaezzat777@gmail.com

D. J. MoldenInternational Water Management Institute, Colombo, Sri Lanka

A. M. GhanemIrrigation and Hydraulics Department, Faculty of Engineering, Cairo University, Cairo, Egypt

practices at branch and tertiary levels, and ensuring that environmental flows are met. Thereis an added advantage of focusing on this tail end region of Egypt that this response wouldlessen vulnerability to reuse of polluted and saline water.

Keywords Performance . Indicators . Irrigation . Efficiency . Actual evapotranspiration .

Productivity . Water saving

Introduction

Water scarcity is a growing global problem challenging sustainable development andplacing a constraint on producing enough food to meet increasing food requirements(Molden 2007). Egypt is one of the countries facing great challenges, due to its aridity anda fixed share of limited Nile water. Because of population growth, the per capita share ofwater renewable resources has dropped dramatically to about700 m3/capita which, byinternational standards is considered the water poverty limit (FAO 2007). The value mayeven decrease to500 m3/capita in 2025 (NWRP 2005). Poor management has been cited asthe most frequent problem of irrigation (Jensen et al. 1990) leading to less than optimal useof limited water resources. Critically important for Egypt, as well as in many countries ofthe world is the need to produce more food with even less water going to agriculture, ascities, industries take an increasing share, and with the recognized need to leave enoughwater for the environment. Egypt with its long running experience provides valuablelessons in this area.

Improving efficiency of irrigation has long been an important water management goal inorder to reduce wastage and save water. However concepts about efficiency have beenevolving as people learn how to deal with scarcity. Seckler (1996) discussed the differencebetween “real” and “paper” water saving noting that return flows from irrigation are oftenreused, and that “savings” on farm or through canal lining are only on paper, and do notnecessarily represent water that can be transferred to more agriculture or another use. Inorder to understand whether savings are real, a cross-scale perspective is required tounderstand what happens to return flows. Water can be saved by reducing losses of usablewater to sinks, reducing non-productive evaporation and reducing water pollution. Kellerand Keller (1995) introduced the concept of effective efficiency, noting that the effectiveefficiency of the Nile reached levels of 91% as compared to reported values of 40 to 50% ofon-farm efficiency. The difference was due to reuse of water as it flows downstream, andthis demonstrated that improving on-farm efficiency does not necessarily lead to real watersavings. This analysis was a milestone in questioning how much water could be saved inthe Nile system, and how to achieve savings. A second concept that has emerged is waterproductivity, or the obtaining more yield or value per unit of water supplied or depleted (seeMolden et al. 2010 for a recent analysis). Water productivity can be achieved by producingmore per unit of water, real water savings and putting the water saved to use, andreallocating water from lower valued to higher valued uses. Improving water productivity isan important necessary step to solve the water scarcity crisis and relieve problems andpressures that degrade the nature resource bases (Molden 2007).

Performance assessment in irrigation and drainage is an activity that supports theplanning and implementation of any improvement project. Bos et al. (2005) defined theperformance assessment process as a systematic observation, documentation andinterpretation of activities related to irrigated agriculture, with an ultimate purpose ofachieving an efficient and effective use of resources by providing relevant feedback to the

216

scheme management at all levels. Bastiaanssen and Bos (1999) stated that to make aperformance assessment oriented approaches effective, it is necessary to retrofit newtechniques and approaches to existing management practices. Satellite measurements canprovide regular information on agricultural and hydrological conditions of land surface.Chemin et al. (2004) added that remote sensing (RS) tools can help in improving watermanagement in three ways: (a) by providing information on the existing patterns of wateruse; (b) by identifying the weakness in the approach to water management; and (c) byassessing in identifying the potential area where there are opportunities for water savings orimproving water use efficiency.

The main objective of this paper is proposing a diagnostic performance assessmentprogram for assessing the irrigation water management, applying it to the old lands of theNile Delta of Egypt and studying the opportunities of improving the management ofirrigation water to achieve real saving of water.

Methodology

A framework for assessing the performance of irrigation water management was proposedand applied for a case study representing the old lands of the Nile Delta of Egypt. Theperformance assessment was measured through the use of a set of selected indicators, whichprovide information about the level of performance of irrigation water management in theNile Delta. The following section defines the selected performance indicators, the datacollection process for calculation of performance indicators and the methods used forprocessing RS data.

Selected performance indicators

Indicators were selected in this study and defined to assess the performance ofirrigation water management as illustrated in Table 1. The indicators selected forstudying the efficiency of irrigation water supply and use and in addition to the economicand physical productivity at the three levels of the irrigation system (main, branch andon-farm level).

Data used in the performance assessment

To calculate the previous selected performance indicators a set of data was required. Someof these are measured and collected ground field data in addition to RS data whichextracted from satellite images for the year 2008–2009.

Tables 2 and 3 show the sources and methods of the data collection used in this study.

Calculation of actual evapotranspiration

Remote Sensing data was used for this study to calculate and map actual evapotranspiration.The satellite images were acquired on different dates within the study period (from April 2008to March 2009). Altogether 49 of Moderate Resolution Imaging Spectoradiometer (MODIS)images were used covering the study period April 2008 to 2009. An attempt has been made toget 4 images for each month within the study period. All the selected images were cloud free,pre-processed for radiometric and geometric correction and were downloaded from https://wist.echo.nasa.gov/wist-bin/api/ims.cgi

217

Tab

le1

Selectedperformance

indicators

anddefinitio

ns

Perform

ance

Assessm

entIndicators

Definitions

Source

Definitionsof

Data

DepletedFractionðDFÞ¼

ETact

PþV

cMolden(199

7)ETactistheactual

evapotranspiratio

nfrom

thegrosscommandarea

(mm)

Bos

etal.(20

05)

Vcisthevolumeof

surfacewater

flow

ing

into

thecommandarea

(mm)

Pistheprecipitatio

non

thegross

commandarea

(mm)

RelativeEvapotranspirationðR

EÞ¼

ETact

ETp

Bos

etal.(200

5)ETactistheactualevapotranspiratio

nfrom

thegrosscommandarea

(mm)

ETpisthepotentialevapotranspiratio

n(m

m)

RelativeWater

Sup

plyðR

WSÞ¼

Irrigatio

nwater

supplyðm

3=haÞ

Irrigatio

nwater

requirem

entsðm

3=haÞ

Levine(198

2)Discharge

atthehead

ofthecanal

Irrigatio

nWater

Requirement=(ETp+Leaching

Requirement+Special

Practices)

Productivity

perunitirrigatio

nwater

supply

¼Yield

ofharvestedcrop½kg

�Volum

eof

suppliedirrigatio

nwater

½m3�

Molden(199

7)Cropyields

(Kg)

Bos

(200

2)Irrigatio

nwater

suppliedat

fieldlevel(m

3)

Produ

ctivity

perun

itwater

consum

ed¼

Yield

ofHarvested

Crop½kg

�Volum

eof

water

consum

edby

ETact½m

3�

Molden(199

7)Cropyields

(Kg)

Irrigatio

nwater

consum

edas

ETactby

thecrop

(m3)

Produ

ctivity

perun

itarea

¼Yield

ofharvestedcrop

½kg�

Total

croppedarea

½ha�

Molden(199

7)Cropyields

(kg)

Totalarea

ofcultivatedcrop

(ha)

Outpu

tperun

itirrigatedarea

ðUS$=haÞ¼

Total

annual

valueof

agricultu

ralproductio

nirrigatedcroppedarea

inthecommandarea

ðincludingmultip

lecroppingÞ

Moldenet

al.(199

8)To

talannual

valueof

agricultu

ralproductio

nreceived

byproducer

(US$)

Totalirrigatedarea

includingmultip

lecropping

(ha)

Outputperunitirrigatio

nwater

supply

ðUS$=m

3Þ

¼Totalannualvalueof

agricultu

ralproductio

nsurfaceirrigatio

nwater

from

outsidetheareaþt

otal

annual

ground

water

pumping

Moldenet

al.(199

8)To

talannual

valueof

agricultu

ral

productio

nreceived

byprod

ucer

(US$)

Totalirrigatio

nwater

supply

(m3)

Outputperunitirrigatio

nwater

consum

edðU

S$=m

3Þ¼

Totalannualvalueof

agricultu

ralproductio

ntotalannualvolumeof

water

consum

edby

ETactonfield

Moldenet

al.(199

8)To

talannual

valueof

agricultu

ral

productio

nreceived

byprod

ucer

(US$)

Totalannu

alvalueof

ETact(m

3)

218

The SEBAL model (Bastiaanssen et al. 1998) was applied using ILWIS software (ITC2001) to generate a spatial distribution of actual evapotranspiration for every acquisition

Table 2 Summary of data used in the study and its sources

Data Type of Data Source of Data

Irrigation water supply • Measured flow rate at maincanal and branch canals

• For the main canal and the branch canals;Water Management Research Institute(WMRI) using the average of dischargeof 4 measurement each month(using current meter)

• Irrigation water supply byfarmer to each study farm

• Pump calibration and collected data(irrigation duration for each field )

Climate Data;temperature, rainfall,humidity, sunshinehours, wind speed

Daily values Meteorological station of agriculture(Sakha weather station)

Crop type Land cover map Bastiaanssen et al. (2009) study landclassification maps for the sameyear 2008–2009

IKONOS images Satellite data used for detectingthe canals boundary

Ministry of Water Resources and Irrigation

MODIS images Satellite data used forcalculation of ETact maps

Download from the internet

https://wist.echo.nasa.gov/wist-bin/api/ims.cgi

ETact and Biomassmaps of Landsat5 images

Processed satellite data Bastiaanssen et al. (2009) study usingLandsat5 images with 30 m resolutionfor the same year 2008–2009.

Productivity Seasonal values • At the main canal level; the averageof collected data from 2 agriculturalcooperatives for El-Gharbeya andKafr El-Sheikh.

• At branch canals level; productivity mapsproduced by Bastiaanssen et al. (2009)

• At on-farm level; collected data fromfarmers at the end of each seasonfor each study farm.

Local and internationalprices

Price per item or material Ministry of Agricultural and LandReclamation (MALR) official records,World Bank statistics.

Table 3 Cropping pattern of the studied branch canals for the year 2008–2009

Season Crop Meet YazidCommand area

Khadigacommand area

Daqaltcommand area

El-Masharqacommand area

Summer Rice 62% 66% 54% 44%

Cotton 9% 5% 9% 20%

Maize 29% 11% 21% 19%

Winter Wheat 60% 19% 58% 52%

Bersseem 23% 49% 18% 19%

Sugar beet 17% 10% 22% 9%

219

day as illustrated in Mohammed et al. (2004). SEBAL model requires the weather data;wind speed, humidity, solar radiation, air temperature to obtain ET from the remote sensingimages..

After computing the ETact for every acquisition day, the meteorological data (Sakhaweather station) were used to calculate daily and monthly reference evapotransipiration byPenman-Monteith equation for Alfalfa (Allen et al. 1998) to convert daily actualevapotranspiration to monthly values through applying the equation of Mohammed et al.(2004) as follows;

ETa mon ¼ ETa day

ETref day� ETref mon

Monthly ETact maps for Meet Yazid command area were produced. The highest value ofETact was in July (203 mm) and the lowest value was in December (46 mm). Figure 1shows the average monthly actual evapotranspiration for the command area.

Description of the selected study area

Meet Yazid Canal is 63 km-long located in the central Delta with total area of about (82,470 ha).It receives water from the right side of Bahr Shebien carrier canal through gravity, at Km96.650. It generally flows in a northern to north-western direction and ends immediately southof El-Burullus Lake. Water is controlled along the canal by the head regulator and four crossregulators, and its end reach forms Gannabiet Sidi-Salem Canal which ends by a tail escape inNo. 8 Drain. Irrigation water flows into branch canals by gravity, and then is lifted frommesqasinto marwas which deliver water to the fields. There is a considerable area which irrigatesdirectly and illegally from branch and main canals. Most of the pumps are powered by dieselengines. Improved branch canals at Meet Yazid command area are operating on continuousflow basis. Unimproved branch canals are operating on rotational basis. The rotation patternvaries seasonally and according to the crops with on and off periods which have severalcombinations as; 4 days on/off, 5 days on/off, 7 days on/off, and 4 days on with 8 days off.

131.3

190.7199.8 203

178.3

140.1

91.1

53.6 4654.8

72.4

122.7

0

50

100

150

200

250

April

May

June Ju

ly

Augus

t

Septe

mbe

r

Octobe

r

Novem

ber

Decem

ber

Janu

ary

Febru

ary

Mar

ch

Month (2008-2009)

ET

act

(mm

/mon

th

Fig. 1 The average monthly values of ETact of Meet Yazid command area

220

The branch canals selected for study were; Khadiga Canal which represents the head,Daqalt Canal which represents the middle and El-Mashrqa Canal which represents the tailof Meet Yazid command area. First, the 3.8 km long Khadiga canal is an earthendistributary canal, located on the left side of Meet Yazid Canal at km 13.01, serving an areaof about (724 ha). The whole canal is operated on rotational basis. The control structure atthe head of the canal is traditional sluice gate (Fahmy Haneen gate). Second, the 11.420long Daqalt Canal is an earthen distributary canal located on the right side of Meet Yazidcanal at km 41.00 serving an area of about (2,247 ha). It has been improved as a partof El-Wassat command area. The whole canal is operated in continuous flow operatedsupply system with varying water levels according to availability of water. Third, the4.2 km long El-Masharqa Canal is located at the tail end of Meet Yazid canal on theleft side at km 57 serving an area of about (866 ha). El-Masharqa Canal has onebranch at km 1.33, which is Sidi Salem Canal. El-Masharqa command area is a partof W-10, the pilot area of the Integrated Irrigation Improvement and ManagementProject IIIMP, which implements new design criteria for Irrigation ImprovementProject (IIP). The design criteria include replacement of downstream control gates bysluice gates provided with automation system. Also, a low cost design of mesqaimprovement was applied in addition to replacing the earthen marwa by PVCpipelines. The data of cropping pattern according to the classification of landsat5images by Bastiaanssen et al. (2009).

On-farm studies were conducted at the Bahr Nemra branch canal. Three fields werechosen which located at the head, middle and tail of Bahr Nemra canal. In addition to threefields (head, middle and tail) along mesqa (El-Bahawat) at the head of the branch canal andalso three fields (head, middle and tail) along mesqa (Sera) at the end of the branch canal.The data collected was for two seasons’ summer and winter. Figure 2 Shows Meet Yazidcommand area map illustrating its location in the Nile Delta of Egypt and the selectedbranch canals study areas and also the on farm study areas.

& Salt water intrusion extends to a distance of about 130 km from the Mediterraneancoast. This would leave only a small triangular zone of fresh ground water aquifer,extending about 35 km north the apex of the Nile Delta (Kashef 1983). Meet Yazidcommand area location extends from the middle to the end of the Nile Delta and thesalinity contour line (1,000 ppm) passes at km 27.37 of Meet Yazid Canal as shown inFig. 3.

Therefore, the downstream of Meet Yazid command area lay in a saline ground waterbasin zone so there is limited opportunity to use the drainage water flowing to ground waterdownstream. Also, the salinity of excess drainage water resulting from the area is 4.2mmhos /cm and is discharged into El-Burullus Lake through open drains (DRI 2007). Withgrowing population and agricultural activities, water pollution is spreading in the deltaregion. Huge amounts of urban municipal and industrial waste water and rural domesticwastes discharge into agricultural drains without treatment. The total sewage volume in theDelta region is about 6.02 MCM/day, or 2.17 BCM/year (Abdel Azim and Allam 2004).Thus, raw sewage flows to drains causing big constraints of the reuse of drainage water.Three pump stations have been shut down in Delta due to heavy pollution. The using ofdrainage water may affect the sustainability of these lands in the long run throughincreasing the salinity of these lands due to the deterioration of drainage water quality. Itwas expected that after applying the IIP, which replaces earthen mesqas by PVC pipelines,the drainage effluent from farms will be reduced. Farmers who rely on drainage water reuse

221

for irrigating their lands will face real problems if they do not receive sufficient irrigation watersupply through improving the water distribution system and applying water according toirrigation requirements. Therefore, at the northernmost end of the Delta there is a potential forwater saving by reducing the amounts of drainage water from agricultural lands and make gooduse of every drop of water before it goes to drainage system and get polluted.

Fig. 2 Map of Meet Yazid command area

222

Results and analysis

The following sections include the results of the applied assessment at the three levels;main canal, branch canals and on-farm. The performance indicators compared against eachother as well as critical and allowable values used to generate recommendations.

Performance indicators at the main canal level

The depleted fraction

The depleted fraction, defined as the ratio of ETact over total inflow (rain plus water supply)(Molden 1997 and Bos et al. 2005), relates parameters of the water balance of an irrigationarea with each other in such a way that water managers obtain information on the actualwater consumed by evapotranspiration process compared to the water supplied to thecommand area. The depleted fraction quantifies the surface water balance excluding thedrainage component. As stated in Bos, et al. (2005) the critical value of the depletedfraction for semi arid regions ranges between 0.5 and 0.7 (average about 0.6). If the annualaverage of the depleted fraction equals about 0.6 water storage in the area is stable, whilewater is stored for lower values of the depleted fraction. The volume of water stored in thearea decreases due to natural drainage and capillary rise if the depleted fraction valueexceeds about 0.6. The monthly depleted fraction values of Meet Yazid command area

Meet Yazid Canal

Nile Branches

Meet Yazid Canal

Bahr Shebien

Lack El-Brullus

Lack Manzala

Lack Edko

LackMary

ut

1000

3000

10000

5000

Main Canals

ISO salinity line in ppm Ground water salinity

Kilometers30 0 60

32 30

31 45

29 30

31 49

30 00

32 30

30 00

29 30

30

1000

1000

1000

3000

3000

5000

5000

1000010000

Legend

N

Damietta BranchRosetta Branch

Fig. 3 the ground water salinity of Nile Delta 2005 (DRI 2007)

223

ranged between 0.48 and 0.54 for the summer season and 0.27 to 0.774 for the winterseason as shown in Fig. 4.

The annual value of depleted fraction was 0.47 which indicating a potential for risingground water table and also increased drainage flow into the downstream environment. Thisdrainage water usually transports a variety of chemicals (salts, pesticides, etc.) (Bos 2004).Some of the drainage water can be reused, but the salinity of drainage water at the NorthDelta area bounded by sea varies from 2,000 to 4,000 ppm, thus the drainage reuse is notrecommended in these areas (Abdel Azim and Allam 2004).

The relative evapotranspiration (RE)

The dimensionless ratio of actual over potential evapotranspiration (Bos et al. 2005) givesvaluable information about crop water-stress. This indicator quantifies reduction inevapotranspiration and detects water stress areas. Bandara (2006) derived a relationshipbetween RE and yield (ton/ha) and concluded that the critical value of RE is 0.65 and thegood performance value of RE is 1 which produces the maximum level of yield. Potentialevapotranspiration was calculated by multiplying monthly reference evapotranspiration,calculated by Penman Monteith equation using meteorological data from Sakha weatherstation, by monthly Kc for each crop. Figure 5 shows the average monthly values of relativeevapotranspiration (RE) which ranged from 1 to 0.63 with an average annual value of 0.84.Therefore, these values did not indicate water stress that can affect crop yield values.

Relative water supply at main canal level

Relative water supply proposed by Levine (1982) is an indicator which helps in measuringthe adequacy of the irrigation water supply compared to the irrigation water demands. It is akey indicator for assessing water management Relative water supply compares the totalwater supply that enters the command area at the head of Meet Yazid Canal against the totalirrigation water requirements for the command area (ETp – effective precipitation +Leaching Requirements + Special practices) according to the actual cropping pattern. WhenRWS is 1, supply equals requirements, while values greater than 1 indicate over supply andvalues less than 1 indicate water shortages.

Depleted Fraction (DF)

0.5370.500 0.495 0.486 0.480

0.541

0.383

0.275 0.270

0.463 0.445

0.774

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

April May June July August September October November December January February March

Month

DF

Fig. 4 Depleted Fraction for Meet Yazid command area for year 2008–2009

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The values of RWS for Meet Yazid command area varied from 0.92 in April whichindicated water shortage to 2.38 in November which indicated over supply of irrigationwater as shown in Fig. 6. The annual average value of RWS was 1.5 which indicates thatwater availability problems in Meet Yazid command area were not due to external shortageof water supply but due to internal factors within the irrigation system.

Economic productivity

The economic productivity indicators are useful when an irrigation system has multiplecrops, especially grain and non grain, like maize, potatoes and fruits. Moreover, theseindicators are useful when compared before and after applying improvement projects tostudy their economic benefits. Also, the economic indicators can be used in irrigationmanagement to assist in setting strategic objectives and measuring progress against thoseobjectives. The annual gross and net value of production was calculated in addition to the

0.92

1.25

1.83 1.83

1.65

1.43

2.38

2.11

1.64

1.87

1.39

1.68

0

0.5

1

1.5

2

2.5

3

April May June July August Septemper October November December January Februry March

Month (2008-2009)

RW

S

RWS

Critical value

Fig. 6 Relative water supply for Meet Yazid command area

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

April May June July August September October November December Janauary Febraury March

Month (2008-2009)

RE

Monthly average of RE Critical value of RE

Fig. 5 Temporal variation of RE for Meet Yazid command area (year 2008–2009)

225

value of output per unit water supply and per unit water depleted by ETact as shown inTable 4. The gross value of production is the yield multiplied by the local price of output,while the net value includes costs of inputs (seeds, diesel, maintenance of pumps, labor,etc.). The net revenue of cultivated crops in Meet Yazid command area were calculated asshown in Table 5. The results show that the higher net revenue per unit area from summercrops was from cotton (1,369 US$/ha), while the percentage of the cultivated area was only9%. Also, in the winter season the higher revenue was from broad beans (1,350 US$/ha)and the percentage of cultivated area was only 5%. Also the values of output per unit waterconsumed by ETact for each cultivated crop in the studied command area were compared asshown in Table 5. Values are favorable when compared to other irrigation systems(Sakthivadivel et al. 1999), and to values of individual grains (rice 0.05 to 0.18$/m3 of ETand wheat 0.04 to 0.30$/m3 of ET, from Molden 2007).

Performance indicators at branch canal level

Two performance indicators were calculated to assess the efficiency of water supply at thethree branch canals represented the head, middle and tail. The Depleted Fraction and theRelative Water Supply indicators were selected and assessed at the three selected branchcanals to study the adequacy of irrigation water supply. The ETact for each branch canalcommand area was calculated using ETact maps produced from MODIS images withresolution 250 m. The irrigation water requirements for the three branch canals werecalculated (ETp – Pe + LR + Special Practices needs). Also, the ETact of rice and wheatfields were obtained from the results of Bastiaanssen et al. (2009) using Landsat imageswith 30 m resolution. The spatial distribution maps of rice and wheat productivity producedby Bastiaanssen et al. (2009) for the same study area were used. The values of theproductivity per unit water consumed by ETact and per unit land were compared for thethree branch canals.

Depleted fraction at the branch canals level

The monthly depleted fraction was calculated for the three branch canals represented thehead, middle and tail of Meet Yazid command area as shown in Fig. 7. The values of DFfor Khadiga Canal varied from 0.86 to 1.62 for the summer season which indicated thatthere was use from groundwater storage and reuse to satisfy shortage. In the winter seasonthe values of DF varied from 0.48 to 0.8. For Daqalt Canal the values of DF varied from0.61 to 1.39 for the summer season and from 0.31 to 0.55 for the winter season whichindicated a potential of water saving from this canal in the winter season. El-Masharqa

Table 4 Economic performance indicators for Meet Yazid command area for the year 2008–2009

Economic Performance Indicators The Economic valuesfor year 2008–2009

Total Annual Gross Value of Agricultural Production 226,706,816 US$

Total Annual Net Value of Agricultural Production 99,090,909 US$

Standard Gross Value of Output Per Unit Area (including multiple cropping) 1726 US$/ha

Gross Value of Output per Unit Irrigation Water Supply 0.11 US$/m3

Gross Value Output per Unit Irrigation Water Consumed as ETact 0.23 US$/m3

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Canal had a DF values varied from 1.23 to 3.82 for the summer season which indicated ahigh drainage reuse rates. Also, the values of DF varied from 0.45 to 0.83 for winter season.

Relative water supply at the branch canals level

The RWS values for the three branch canals Khadiga, Daqalt and El-Masharqa weremonthly calculated as shown in Fig. 8. The results indicated a water shortage in the summerseason for Khadiga and EL-Masharqa canals which represent the head and the tail end,respectively. On the other hand, there was an oversupply of irrigation water in the winterseason for all canals especially Daqalt canal which represents the middle of the study areaand applies a continuous flow water supply system.

The shortage of water supply in the summer season was due to extensive rice cultivationespecially at the head of the study area. The area of rice cultivation was 66%, 54%, and 44% forKhadiga, Daqalt and El-Masharqa canals, respectively. The allowable area for rice cultivation

1.2

1.6

1.4

1.4

1.1

0.6 0.6

0.7

0.5

0.8

0.70.

8

0.6 0.7

0.7 0.

9

0.8

0.3

0.3

0.3 0.

5 0.5

1.4

1.3

2.8

3.8

3.1

1.4

1.2

0.5

0.5 0.

6

0.6

0.8

1.3

0.8

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

AprilMay

June

July

August

September

October

November

December

January

FebruaryMarch

Month (year 2008-2009)

Dep

lete

d F

ract

ion

Khadiga Canal (H)

Daqalt Canal (M)

El_Masharqa Canal (T)

Fig. 7 the monthly Depleted Fraction values for the studied branch canals

Table 5 Net revenue of each crop cultivated in Meet Yazid command area for the year 2008–2009

CropName

Area%

AverageCropYield(ton/ha)

The amount ofETact per seasonfor each cropmm/season

The valueof inputUS$/ha/season

The valueof outputUS$/ha/season

The value ofoutput per unitwater consumedby ETact US$/m

3

Net valueof revenueUS$/ha/season

Rice 62 8.3 779 1237 1907. 0.24 617

Maize 28.6 7.7 740 979 1246 0.17 267

Cotton 9 1.1 913 1356 2725 0.30 1369

Sugerbeet

11.6 42.8 555 1163. 1570 0.28 406

Berseem 23 47.6 746 1096 1308 0.17 211

Broadbeans

5 4.0 697 562 1912. 0.27 1350

Wheat 60 6.4 634 627 1883 0.30 1256

227

was 50% for Daqalt and El-Masharqa canals which are part of Kafr El-Sheikh Governorate toovercome salinity and 20% for Khadiga Canal, which is a part of El-Gharbeya Governorate.Also, at Daqalt Canal the water supplied was higher than the irrigationwater requirements in thewinter season because water supply was not according to actual cropping pattern needs.Therefore, real data about cropping pattern should be available to enable correct calculation ofirrigation water requirements and supply irrigation water according to actual needs.

Physical productivity at branch canal level

The average values of ETact were calculated using RS data for rice and wheat crops at eachbranch canal. The values of productivity per unit water consumed by ETact for rice andwheat crops were calculated as shown in Fig. 9. The results indicate that the difference inproductivity values between the three branches was very small. That is because there wasno crop water stress in the whole area. The farmers overcome shortage problems byirrigating their lands from drains which can affect the sustainability of their lands in thefuture by increasing soil salinity. Also, the productivity per unit land was assessed andcompared for the three canals as shown in Fig. 10. The results show a decline of rice

Relative Water Supply

0.460.68 0.67 0.63

1.3

1.761.51

0.72

1.41.66 1.62

1.16 1.241.44

4.754.5

3.77

4.14

2.11

0.360.21 0.23 0.3

0.59 0.63 0.55

1.34

0.75

1.191.03

0.520.45

0.911.08

1.281.36

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

April May June July August Sep Oct Nov Dec Jan Feb March

Month (2008-2009)

RW

SKhadiga canal (Head)Daqalt canal (Middle)El-Masharqa canal (Tail)Critical value

Fig. 8 Relative water supply for the selected branch canals

Productivity per unit water depleted as ETact

1.08 1.10

0.91

1.05

0.940.92

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Khadiga (H) Daqalt (M) El_Masharqa(T)

Kg

/cu

.m

Rice Productivity per unit waterdepleted as Etact(kg/cu.m)

Wheat Productivity per unit waterdepleted as Etact(kg/cu.m)

Fig. 9 Water productivity com-parison between branch canals at(Head, Middle, Tail)

228

productivity per unit area by about 10% from head to tail while no change in wheatproductivity can be noticed.

Performance indicators at the on-farm level

Three performance indicators were selected to study the efficiency of irrigation water use atthe on-farm level. The Depleted Fraction indicator was calculated for rice and wheat fields.Also, the Relative Water Supply indicator was used to assess the efficiency of water appliedto each field. Moreover, the productivity per unit water applied by farmers and also per unitwater consumed by ETact was assessed and compared for the selected rice and wheat fields.

Depleted fraction at the on-farm level

The DF was calculated and compared for the rice and wheat fields as shown in Figs. 11 and 12.For rice fields, the values of depleted fraction varied from 0.29 to 0.54, which indicates ampledrainage return flows, water returns to drainage and saline sinks. For wheat fields, the valuesof DF varied from 0.88 to 1.4. The type of soil in the study area is heavy clay and at winterseason the ground water table rises to reach 0.65 m to 1.5 m below ground, so there is aground water contribution which was estimated as 0.25 mm/day as stated in Doorenbos andPruitt (1992).

Productivity per unit area (ton/ha)

8.708.09

5.98 6.11 5.89

8.33

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

Khadiga (H) Daqalt (M) El_Masharqa(T)

ton

/ha

Average Rice Yield (Ton/ha)

Average Wheat Yield (Ton/ha)

Fig. 10 Land productivity com-parison between branch canals at(Head, Middle, Tail)

Rice fields DF

0.44

0.54

0.44

0.54

0.29

0.53

0.35

0.54

0.34

0

0.1

0.2

0.3

0.4

0.5

0.6

Head Middle Tail Head Middle Tail Head Middle Tail

Direct Bahr Nemra El-Bahawat Mesqa atthe Head of Bahr

Nemra

Sera Mesqa at the Tailof Bahr Nemra

Fig. 11 Depleted fraction for ricefields

229

Relative water supply at the on-farm level

The values of irrigation water applied per unit area in rice fields varied from 14,682 m3/ha/season to 27,057 m3/ha/season. The irrigation water requirements per unit area of rice(ETp + leaching requirements + special practices needs) was 13,887 m3/ha/season. On theother hand, the values of irrigation water supply in wheat fields varied from 3,771 m3/ha/season to 6,583 m3/ha/season and the irrigation water requirements per unit area forwheat fields (ETp– Pe – Gw + LR) was 3,066 m3/ha/season. Relative water supplyindicator at the farm level studies the adequacy of irrigation water applied by farmers. Itis calculated by dividing the irrigation water applied by farmers over the irrigation waterrequirements for each field. The results of RWS of rice fields varied from 1.1 to 1.9 asshown in Fig. 13. The values of RWS for wheat fields varied from 1.2 to 2.1 as shown inFig. 14. The values of irrigation water supply indicator depended mainly on the farmerbehavior not the location along the canal or the mesqa. All fields had satisfied theirrequirements of irrigation and some fields had over irrigation values.

Physical productivity at on-farm level (kg/m3)

Water productivity indicators proposed by Molden (1997) quantify the values of crop yield perunit water supplied or per unit water consumed by ETact. The values of rice productivity perunit water supply for the selected studied fields varied from 0.31 to 0.57 kg/m3 and the riceproductivity per unit water depleted by ETact varied from 0.9 to 1.16 kg/m3 as shown inFig. 15. The productivity of wheat per unit water supplied varied from 0.74 to 2.10 kg/m3. Theproductivity of wheat per unit water depleted by (ETact) varied from 0.77 to 1.29 kg/m3 asshown in Fig. 16. The water productivity per unit water supply of wheat fields varied more

Wheat fields DF

1.36

0.88

1.31

1.05

1.36 1.44

0.89

1.40 1.47

00.20.40.60.8

11.21.41.6

Head Middle Tail Head Middle Tail Head Middle Tail

Direct Bahr Nemra El-Bahawat Mesqa atthe Head of Bahr

Nemra

Sera Mesqa at theTail of Bahr Nemra

Fig. 12 Depleted fraction forwheat fields

RWS for rice fields

1.31.1

1.31.1

1.91.7

1.1

1.6

1.1

0

0.5

1

1.5

2

2.5

Head Middle Tail Head Middle Tail Head Middle Tail

Direct Bahr Nemra El-Bahawat Mesqa atthe Head of Bahr

Sera Mesqa at theTail of Bahr Nemra

Fig. 13 Relative water supplyfor rice fields

230

than rice fields which indicate opportunity for improvement. Zwart and Bastiaanssen (2004)based on review of 84 literature sources stated that the globally measured average waterproductivity per unit water depleted by (ETact) is 1.09 kg/m

3 for rice and wheat. For the studiedfields, the average values of water productivity per unit water depleted by ETact were 1.04 and1.05 Kg/m3for rice and wheat respectively, so these values are within the average global levels.

Discussion and recommendations

This cross scale performance assessments provides important insights into water use andproductivity in Egypt. On the one hand the performance of yield and water productivityagainst international standards is uniformly quite good, independent of location. Theevaporative fraction is uniformly high as the average annual value of Relative Evaporativewas 0.84. In contrast, there is high variability in relative water supply and depleted fractionat the farm and mesqa level. This also varies between improved and unimproved canals.Overall this indicates little water stress in spite of the situation in Egypt noted as one asseverely water stressed. On the other hand, low values of depleted fraction along the maincanal indicate that there is ample drainage flow into the Northern Lakes and into theMediterranean, indicating possible scope for real water savings.

RWS for wheat fields

1.3

2.1

1.4

1.7

1.3 1.2

2.1

1.3 1.2

0

0.5

1

1.5

2

2.5

Head Middle Tail Head Middle Tail Head Middle Tail

Direct Bahr Nemra El-Bahawat Mesqa atthe Head of Bahr

Sera Mesqa at the Tailof Bahr Nemra

Fig. 14 Relative water supplyfor wheat fields

Rice productivity per unit water (kg/cu.m)

0.48 0.

54

0.46

0.56

0.31

0.40

0.48

0.37

0.57

1.08

1.00 1.

05

1.05

1.06

1.16

0.90

1.05

1.05

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

Head Middle Tail Head Middle Tail Head Middle Tail

Direct Bahr Nemra El-Bahawat Mesqa at the Head ofBahr Nemra

Sera Mesqa at the Tail of BahrNemra

kg/c

u.m

Rice Productivity per unitirrigation water supply (kg/cu.m)

RiceProductivity per unit waterDepleted as Etact (kg/cu.m)

Fig. 15 Rice productivity per unit water (kg/m3)

231

The analysis of water savings potential is confounded by drainage water reuse. Acommon mistake has been to focus on on-farm efficiency and conclude that increasing itwill save ample water in the Nile system. This is an incorrect conclusion when water isbeing reused. Moreover, the uniform value of relative evaporation indicates that somehowall farmers get ample water supply, and so one could question whether equity of supply is amajor issue. It was quite evident from the analysis that in periods of water stress farmerswere using drainage flows. However, salinity increases getting closer to the Sea, and reuseis not advisable in the northernmost areas. Furthermore, many of the drains are pollutedwith urban wastes posing a health risk limiting practical options for reuse.

& At the main canal, the monthly DF values for Meet Yazid command area varied from0.27 to 0.77, with an annual value of 0.47, which indicates high volumes of drainagewater flow into the Lake Burullus or to the Mediterranean Sea. Some of this flow meetsan environmental need, as Lake Burullus does require some inflow for its survivalultimately the water saving potential can be calculated by the present outflow to LakeBurullus less environmental flows. A further environmental flow analysis is warranted.Given the volume of outflow to the North it appears that there is some scope for realwater savings. Molden et al. (1996) calculated the depleted fraction for the entire Nileand the value was 0.84.

& The difference between improved and unimproved canals in terms of water supply,water productivity or water savings is not evident. Daqalt and El-Masharqa Canals areimproved canals and have continuous flow water supply with varied levels according towater availability. The annual average of DF values were 0.65 and 1.48 , for theimproved canals Daqalt and El-Masharqa, respectively and 0.94 for Khadiga Canal(unimproved) which operates under rotation water supply system. The DF values ofKhadiga Canal and El-Masharqa Canal indicated that there is an irrigation water supplyshortage. So, even that El-Masharqa Canal is an improved canal and apply a continuousflow system, it still has an irrigation water supply shortage due its location at the end ofMeet Yazid command area. At the other hand, Daqalt Canal which representing the

Wheat productivity per unit water (kg/cu.m)

1.97

0.74

1.25

1.39

1.74

2.10

0.99

1.53

1.52

1.29

0.78 0.

86

1.22

1.14

1.29

1.03

0.97

0.91

0.00

0.50

1.00

1.50

2.00

2.50

Head Middle Tail Head Middle Tail Head Middle Tail

Direct Bahr Nemra El-Bahawat Mesqa at the Head of BahrNemra

Sera Mesqa at the Tail of Bahr Nemra

kg/c

u.m

Wheat productivity per unit irrigationwater supply (kg/cu.m)

Wheat Productivity per unit waterDepleted as Etact(Kg/cu.m)

Fig. 16 Wheat productivity per unit water (kg/m3)

232

middle of the command area had over supply in the winter season as water suppliedreached 4.7 times the canal irrigation water requirements in November. The continuousflow system which was introduced by IIP was intended to reduce the amount of watersupply to canals while increasing the time of water availability so farmers can arrange ascheduling system between them to irrigate their lands and overcome over irrigationproblems and achieve equity between head and tail of the branch canals commandareas. Therefore, IIP still didn’t achieve their goal of achieving equity and reducing theamount of water supply.

& Working at one level of the irrigation system with a target of saving water will beoutbalanced by efficiency losses elsewhere. All the previous and current activities forimproving old land irrigation system improvement in Egypt concentrate on increasingonly the distribution efficiency through applying continuous flow system at branchcanals level, replacing old earthen mesqa by PVC pipelines and later replacing earthenmarwa by PVC pipelines. The results of DF at the on-farm level indicated a largevariation between fields. Thus there is an opportunity for improving this indicator iffarmers would reduce application to their field. However, there is little incentive to doso, especially with ample water supplies available in the canal system. Also, the on farmmanagement activities such as land leveling, agronomic practices, modified cultivationmethods and also training farmers will lead to improve the level of applicationefficiency. Whether this leads to real water savings is dependent on whether that wateris reused. Closer to the North where the opportunities for reuse decline, this is anexcellent strategy. One way to achieve it is to reduce supplies to farmers, and a secondis to increase the price of water to farmers, but this has inherent difficulties at present(Perry et al. 1997) and is not being discussed as an option.

& By comparing the values of DF and RWS for the whole command area, branch canalsand on-farm levels it can be concluded that there is a potential of water saving byapplying integrated strategy for improving the three levels. The RWS values at the threestudied levels showed a mismatch between demand and supply. Achieving matchingbetween demand and supply requires real feedback of the actual cropping pattern toenable correct calculation of irrigation water requirements and good planning ofirrigation schedules.

A major first step would be to reduce the supply of water into the Meet Yazid commandarea, and either keep the water stored elsewhere in the system (for example in Lake Nasser)or used elsewhere in the system. As a response to this reduced supply, the management oflower levels of the system would have to tighten in order maintain high productivity andequity. Ultimately this could reduce drainage outflows, although caution would have to betaken to ensure environmental flows. One of the difficulties in this strategy is the lack ofstorage downstream in the Nile system, and water managers have to do a good job atmatching supply and demand.

& Organizations such as WUA’s or water managers at all levels (mesqa, branch canal anddistrict level) can provide the water distribution sector of the MWRI with data about thereal cropping pattern activities in advance of cultivation and also receive the data oftiming and scheduling of irrigation water supply at each branch canal that in turn canachieve matching between demand and supply and also reduce the amounts of watersupply to canals which consequently enforce farmers to irrigate precisely. Also, usingmodern strategies for improving irrigation water supply management to achievesustainable water use is becoming essential as efficient management of land and water

233

resources in irrigated agriculture requires comprehensive knowledge of many variablesincluding climate, soil, land use, crops water availability, water distribution networks,management practices, etc. and most of these data should be integrated and used inirrigation management and planning. Thus, the use of GIS and other moderninformation systems in association with real data from RS and also getting the realfeedback of the cropping pattern in advance from farmers through WUA’s gives a greatopportunity for better management of natural resources. Moreover, applying on-demandwater supply will achieve reliability of water delivery and that can be achieved usingrotation flow system or continuous flow system. What would be important is receivingthe real data about cropping pattern in advance to enable planning of good irrigationschedule that would help in reducing the gap between demands and supply.

& Installing controlled sub-surface drainage system is recommended to reduce the effluentof drainage water and save irrigation water especially at the downstream end of thesystem. The controlled sub-surface drainage is consist of a control structure at drainageoutlet or a weir placed in the open collector drain allows the water table to be artificiallyset at any level between the ground surface and the pipe drainage level, so promotingroot water extraction. As an example, the ETact of rice fields at the on-farm study areawas 7,943 m3/ha/season and the water supply varied from 14,683 to 27057 m3/ha/season. Rice has substantial peak water requirements for land preparation but this wateris not totally evaporated, it essentially flows back to drains and unconfined aquifers.Reducing the amounts of drainage water from rice fields by installing controlleddrainage systems would result in saving water and improve the rice productivity perunit water supply.

& The potential for increased productivity through improved irrigation seems limited asthe average yields are already quite high. Therefore, increasing agricultural revenue(more value per drop) should have more attention to achieve optimum use of irrigationwater by raising the value of water productivity. It can be concluded that there may be ascope to increase water productivity by shifting towards higher valued crops. It isimportant to study and propose new plans for changing cropping pattern towardoptimization of productivity output values to achieve higher value of water productivity.Also, the values of productivity per unit water supply at farm level showed variationbetween fields that indicated an opportunity for improvement through reduction of theamounts of irrigation water apply by farmers.

& A shift in thinking is required in the management of irrigation waters. A first is toconsider performance across scale. A second is to focus more on quality considerations.

Conclusion

This paper presented a cross-scale performance assessment tool for improving themanagement of the irrigation water to achieve efficient, productive and effective irrigationand drainage system. A diagnostic performance assessment program was proposed toprovide relevant feedback to the scheme management at all levels. Applying the proposedperformance assessment program for assessing the irrigation water management of oldlands in the Nile delta of Egypt resulted in highlighting areas that should be considered toimprove the irrigation water management in the old lands of the Nile Delta and to achievereal saving of water. The assessment at the main canal level showed that 53% of the annualirrigation water supply returned to drainage and saline ground water sinks indicating anoversupply of water, and a potential for water savings. It is important to note that

234

opportunities for reuse reduce substantially close to the Northern end of the deltabecause of saline groundwater and drainage water, and that there is simply no moreland on which water could be reused. This is in contrast to Upper Egypt where thereis ample scope for reuse downstream. Thus this Delta area is a prime location toachieve real water savings.

The RWS values indicated a potential of water saving if matching between demand andsupply achieved by reducing the amount of water supply in winter season (November andDecember) as ETact values were low and the winter crops were not yet fully covering theground. Strategies for reducing drainage outflow include reducing supplies into the entirearea, and taking other measures such as applying controlled sub- drainage systems in areaswhere there is high salinity, or at the most downstream parts of the system. A reduction insupply would require that farmers and water mangers change their practices in response.More precise distribution and supply to farmers could cause a reduction in high RWSvalues through great application efficiency. The branch canals assessment showed non-uniformity in water distribution and mismatching between demand and supply, even in the“improved” areas. This highlighted the need for studying the efficiency of continuous flowsystem and its suitability to be applied at all the branch canals of Meet Yazid commandarea. Moreover, a uniformly high value for relative evaporation shows that there is littlewater stress, and farmers do get water from other sources, namely drains and groundwater.The results of economic and physical productivity assessment showed that the potential ofraising productivity per unit water consumed by ETact will be limited because the yieldswere already high. Therefore working for the optimization of the returns per unit water willplay a vital role to produce more value per drop of water. That could be achieved bymodifying the cropping pattern and shifting to higher valued crops to achieve higher returnsper unit water.

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