anand agricultural university, anand –388 110, gujarat 2/s-iii/mc varshneya.pdf · 2008-03-02 ·...
TRANSCRIPT
Validation of Astro-m
eteorological Rainfall
Forecast for Gujarat
M.C. Varshneya,
V.B. Vaidya, VyasPandey, A.M
. Shekhand B.I. Karande
Anand Agricultural University,
Anand –388 110, Gujarat
Agro
Agro
Agro
Agro- ---climatic Zones of Gujarat State
climatic Zones of Gujarat State
climatic Zones of Gujarat State
climatic Zones of Gujarat State
Zone –ISouth Gujarat (Heavy Rainfall Area)
Zone-V North W
est Zone
Zone-IISouth Gujarat
Zone-VI North Saurashtra
Zone-IIIMiddle Gujarat
Zone-VII South Saurashtra
Zone-IVNorth Gujarat
Zone-VIII Bhal& Coastal Area
Rainfall 250 –500 mm
500–900 mm
800–1000 mm
400–700 mm
700–1000 mm
600–800
1000–1500 mm
>1500 mm
625-1000
Arnej
Bhal& Coastal
zone
Zone VIII
750-900
Junagadh
South Saurashtra
Zone VII
400-700
Rajkot
North Saurashtra
Zone VI
350-550
Bhuj
North W
est zone
Zone V
625-835
SK Nagar
North Gujarat
Zone IV
800-1000
Anand
Middle Gujarat
Zone III
1200-1500
Surat
South Gujarat
Zone II
1500-2500
Navsari
South Gujarat
(Heavy rainfall)
Zone I
Rainfall
range
(mm)
HQ
Location
Agro-climatic zones of
Gujarat
Nakshtra-Charanwise forecast
For Gujarat
Based on astrology, Anand Agricultural
University, Anand in 2005 prepared
Nakshtra-Charanwise forecast for eight agro
climatic zones of Gujarat.
The validation of this forecast on
Yes/No basis indicated that accuracy varied
betw
een 42 %
to 73% for various zones.
50%
In Adra, Pushya(3-4charan) Ashlesha(1
stcharan), Purva(4
thcharan) and Uttara
(1-2 charan) the
rainfall was as per forecast with some deviation.
In rest of the Nakshatrathe forecast was not valid.
BhalZone
73%
In Adra. Pushya(1,3,4 charan), Ashlesha( 1-3 charan), Purva(2-4 charan) and Uttara
(1-2 charan)
the rainfall was as per forecast but with less quantity.
South Saurashtra
73%
In Adra, Pushya(3-4 charan), Ashlesha(1-2 charan), M
agha( 1,3, and 4
thcharan), Purva, Uttara
(1-
2 charan) the actual rainfall was as per forecast with deviation.
In rest of the Nakshatrathe rainfall was very less than forecasted.
North
Saurashtra
42%
In Adra
(2-3 charan), Pushya(3-4 charan), Purva(3-4 charan) and Uttara
(1-2 charan), the actual
rainfall was as per forecasted rainfall with some deviation.
Rainfall was forecasted in Ashleshabut there was no rainfall. . In rest of the Nakshatrathe rainfall
was very less than forecasted
North-west
Gujarat
61%
Adra, Pushya(2 to 4 charan), Ashlesha(1
stcharan), Purva(3-4 charan), Uttara
(1-2 charan) was
found comparable with actual rainfall. Forecasted amount was less than actual rainfall
North Gujarat
58%
Adra, 3rdand 4
thcharanof pushya, 1stand 2
ndcharanof Ashlesha, 3rdand 4
thcharanof Purvaand
2ndcharanof Uttara
Nakshatra, rainfall was recorded as per forecast
Middle Gujarat
73%
In 3
rdand 4
thcharanof Adra
and PurvaNakshtraand 1
stand 2
ndCharanof Uttara
Nakshatra, the
actual rainfall was as per forecast. Amount was little bit over/under estimated.
Less rainfall was recorded in Punarvasu
and M
aghaNakshatraas compared to rainfall forecast
South Gujarat
69%
In 3
rdand 4
thcharanof Adra
and PurvaNakshtraand 1
stand 2
ndCharanof Uttara
Nakshatra, the
actual rainfall was as per forecast. Amount was little bit over/under estimated.
Less rainfall was recorded in Punarvasu
and M
aghaNakshatraas compared to rainfall forecast
South Gujarat
(heavy rainfall)
Ratio
Scores
Salient features of agreement or disagreement
Agroclimatic
Zones
In the year 2006, almanac was
prepared by Anand Agricultural
University, Anand, to predict rainfall
distribution in next Monsoon season on
temporal (day to day) and spatial
(different zones) basis, for the farm
ers
of Gujarat state.
This calendar was distributed in 18,600
villages in 225 Talukasof 25 districts of
Gujarat state.
Sample page
Of AAU
almanac
July -2006
Validation of AAU Rainfall prediction calendar during 2006
for Gujarat
Skill score (%)
52
51
52
63
40
Average
50
40
52
65
43
Bhal& Coastal Zone
49
53
48
61
33
South Saurashtra
48
47
48
42
57
North Saurashtra
50
57
52
61
30
North-W
est Gujarat
56
57
52
74
40
North Gujarat
52
50
58
61
37
Middle Gujarat
53
50
52
71
40
South Gujarat
55
53
58
65
43
South Gujarat (Heavy
rainfall)
Average
September
August
July
June
AgroclimaticZone
Methodology for AAU M
onsoon
Research Almanac preparation
1.NakshatraPraveshof Sun: The Kundaliat
the time of Sun’s entry into each Nakshatrais
casted
for each required place (i.e. district)
for the period of Rainy Season. This gives
average rainfall for a period of 12-13 days for
that Nakshatra, at that place.
Methodology for Calendar Preparation
2.
NakshatraCharanPraveshof Sun: The Kundaliat the
time of Sun’s entry into each NakshatraCharanis
casted
for each required place (i.e. district) for the
period of Rainy Season. This gives average rainfall for
a period of 2-3 days for that NakshatraCharan, at
that place. Daily rainfall was predicted by using
Chandra Nakshatra.
A finer astrological technique was used to
distinguish planetary positions/aspects between two
adjoining districts.
Methodology for calendar preparation
3. From each Kundali, various aspects like Mandalof the
Lagna, Planets in SaptanadiChakra, Vedhasamongst
the planets, and different aspects between planets like
Yuti, Pratiyuti, NavapanchamYoga, Kendra Yoga, etc.,
are taken into account. Importance is given if a planet
changes its direction (Vakrior Margi), changes Rashior
Nakshatra, or becomes Astaor Udita.
4. Similarly, Poornimanta(Full moon day) and Aamanta
(No moon day) Kundalisare cast for predictions.
Kundalisare also cast for eclipses. Effects of sighting
comets are also considered.
Meteorological Inputs used in the calendar
1.
Rainfall probability of getting ≥10 mm
rainfall in standard M
W was calculated by
Markov chain model, is given for each district
(Data of weekly rainfall for 50-100 years was
used for analysis).
2.
Monthly norm
al rainfall is given along with
projected rainfall for each month for each
district.
3.
Monthly norm
al Maximum and M
inim
um
temperature for each district is given.
•Computation of Rainfall Projection:
The
pre
dic
ted rai
nfa
ll inte
nsity
on d
aily
bas
is
viz
. N
o rai
nfa
ll, Low
, M
ediu
m, H
eavy a
nd
Ver
y H
eavy for ea
ch d
istric
t (2
5) of G
uja
rat
stat
e from
June
to O
ctober
month
was
use
d to
quan
tify
the
rain
fall a
mount of th
e stat
e.
Crite
ria
for quan
tify
ing d
aily
rai
nfa
ll fro
m
qual
itat
ive
pre
dic
tion for distric
ts u
nder
eac
h
Agricu
ltura
l U
niv
ersity
of th
e re
spec
tive
regio
n
was
dec
ided
bas
ed o
n fre
quen
cy a
nal
ysis fo
r
giv
en rai
nfa
ll inte
nsity
and u
sed in the
cale
ndar
.
100
70
25
60
South
Gujarat
(NAU, Navsari)
4
50
25
61
0For Kutchdistrict*
3
50
30
10
20
North
Gujarat
(SDAU, Dantiwada)
and
Saurashtra
(JAU, Junagadh)
2
75
35
10
20
Middle
Gujarat
(AAU, Anand)
1
Very
Heavy
Heavy
Medium
Low
No
Rain
Daily Rainfall quantification (mm)
Name
of Region /
SAU
Sr.
No.
Criteria for quantifying daily rainfall from qualitative
prediction in different regions of the state.
* Since the rainfall recorded in Kutch
is very low, therefore, separate
intensity was considered for this district in North Gujarat region.
Monthly projected and normal rainfall (mm) for
districts under Middle Gujarat
1011
(808.7
)8
(27.8
)250
(133.2
)282
(223.2
)437
(307.4
)34
(117.1
)V
adodara
824
(917.7
)6
(20.4
)212
(160.1
)258
(266.3
)322
(350.1
)26
(120.8
)Panch
mahal
1011
(792.2
)8
(7.3
)252
(121.0
)282
(254.9
)445
(312.2
)24
(96.8
)K
heda
824
(774.3
)6
(26.6
)212
(153.2
)258
(247.8
)322
(240.4
)26
(106.3
)D
ahod
1010
(819.2
)6
(7.8
)292
(119.4
)290
(302.2
)388
(280.6
)34
(109.2
)A
nand
805
(667.6
)36
(11.0
)122
(136.1
)403
(186.8
)230
(257.3
)14
(76.4
)A
hm
edabad
Tota
lO
ctober
Septe
mber
August
July
June
Month
+25.0
Vadodara
6
-10.2
Panch
mahal
5
+27.6
Kheda
4
+6.4
Dahod
3
+23.3
Anand
2
+ 20.0
Ahm
edabad
1
Rainfall Projection (%
departure from norm
al)
Name of District
Sr. No.
Percent departure from normal for projected rainfall
(June to October) for districts under M
iddle Gujarat
Monthly projected and normal rainfall (mm) for districts
under North Gujarat
92
(331.6
)4
(9.4
)15
(49.1
)52
(97.5
)21
(144.0
)0
(31.6
)K
utc
h
916
(726.3
)8
(10.6
)214
(125.6
)262
(230.6
)418
(280.6
)14 (78.9
)Sabark
anth
a
810
(567.0
)36
(8.1
)112
(95.5
)378
(168.8
)278
(230.7
)6
(63.9
)Pata
n
810
(578.9
)36
(5.7
)112
(109.1
)378
(176.6
)278
(228.5
)6
(59.0
)M
ehsa
na
810
(638.2
)36
(6.4
)112
(41.5
)378
(221.5
)278
(301.9
)6
(66.9
)G
andhin
agar
802
(660.6
)36
(10.4
)114
(89.0
)378
(220.0
)270
(277.4
)4
(63.8
)Banask
anth
a
Total
Oct
Sept
August
July
June
Month
-72.3
Kutc
h6
+ 26.1
Sabark
anth
a5
+ 42.9
Pata
n4
+ 39.9
Mehsa
na
3
+ 26.9
Gandhin
agar
2
+ 21.4
Banask
anth
a1
Rainfall Projection (%
Departure from norm
al)
Name of District
Sr. No.
Percent departure from norm
al for projected rainfall (June
to October) for districts under North Gujarat
Monthly projected and normal rainfall (mm) for
districts under South Gujarat
2291
(1861.8
)24
(31.8
)626
(302.9
)585
(497.5
)969
(691.4
)87
(338.2
)V
als
ad
1887
(1062.6
)24
(26.7
)530
(173.4
)585
(231.1
)680
(427.4
)68
(204.0
)Sura
t
1887
(1379.7
)24
(34.7
)530
(218.6
)585
(328.1
)680
(555.6
)68
(242.7
)N
avsa
ri
2170
(1754.8
)18
(34.2
)526
(296.7
)665
(433.2
)874
(723.5
)87
(267.2
)N
arm
ada
2291
(1783.6
)24
(56.7
)626
(303.3
)585
(514.5
)969
(676.9
)87
(232.2
)D
ang
2107
(682.7
)18
(11.4
)520
(117.8
)608
(263.3
)874
(201.0
)87
(89.2
)Bharu
ch
Tota
lO
ctSept
August
July
June
Month
+23.1
Vals
ad
6
+ 77.7
Sura
t5
+36.8
Navsa
ri4
+23.7
Narm
ada
3
+28.4
Dang
2
+ 208.6
Bharu
ch1
Rainfall Projection (%
Departure from norm
al)
Name of District
Sr. No.
Percent departure from norm
al for projected rainfall (June
to October) for districts under South Gujarat
Monthly projected and normal rainfall (mm) for
districts under Saurashtra
762
(387.1
)36
(11.0
)110
(53.9
)370
(106.6
)230
(149.0
)6
(66.6
)Sure
ndra
na
gar
810
(574.7
)36
(17.6
)112
(80.0
)378
(135.8
)278
(248.2
)6
(93.1
)R
ajkot
762
(596.7
)36
(8.4
)112
(64.5
)378
(115.8
)230
(248.7
)6
(111.8
)Porb
andar
770
(840.7
)36
(28.1
)112
(122.8
)378
(175.5
)230
(351.5
)14
(162.8
)Ju
nagadh
762
(545.8
)36
(10.8
)112
(40.6
)378
(185.8
)230
(202.1
)6
(106.5
)Ja
mnagar
786
(577.8
)36
(21.6
)112
(111.5
)354
(146.5
)278
(207.1
)6
(91.1
)Bhavnagar
810
(533.2
)36
(25.1
)112
(102.2
)278
(114.7
)278
(192.2
)6
(99.0
)A
mre
li
Tota
lO
ctober
Sept
August
July
June
Month
Percent departure from normal for projected rainfall
(June to October) for districts under Saurashtra
+ 51.9
Amreli
1
+ 96.8
Surendranagar
7
+ 40.9
Rajkot
6
+ 27.7
Porbandar
5
-8.4
Junagadh
4
+ 39.6
Jamnagar
3
+ 36.0
Bhavnagar
2
Rainfall Projection (% Departure
from norm
al)
Name of
District
Sr.
No.
Rainfall Projection
(Zonew
ise% Departure from Norm
al)
•Middle Gujarat-
+15.4%
•North Gujarat-
+14.2%
•South Gujarat-
+ 66.4%
•Saurashtra-+47.4%
•Gujarat state as a whole :-
+35.9%
Yes/No Skill score (%) of rainfall prediction in AAU’s
Calendar during June to October 2007.
58.8
78.3
43.9
68.2
39.6
63.3
Saurashtra
iv.
73.1
88.2
48.9
87.1
76.9
64.5
South
Gujarat
iii.
63.3
82.2
43.4
63.5
55.4
72.2
North
Gujarat
ii.
67.9
87.6
38.3
83.9
57.4
72.2
Middle
Gujarat
i.
Avg.
Oct.
Sept.
Aug.
July
June
Region
Sr.
No.
65.9
77.4
63.3
64.5
71.0
53.3
H.S. Nimavatfor
Gujarat state
V
67.3
77.4
63.3
64.5
64.5
66.7
PravinbhaiVora
for Gujarat
IV
66.1
90.3
63.3
45.4
61.3
70.0
Sudhakar
Joshi
for Anandstation
III
55.5
93.5
50.0
43.3
48.8
41.9
Dhansukh
Shah
for Saurashtra
II
65.8
84.1
43.9
75.7
57.3
68.1
AAU’s Monsoon
Research
Almamnac-2007
State Average
I
Average
Oct.
Sept.
August
July
June
Name
of Astro-
meteorologists
Sr.
No.
Yes/No skill score (%) of rainfall prediction given by different
Astro-m
eteorologists for Gujarat during 2007.
•On an average Monsoon Research Almanac
published by AAU, Anandhas shown 65.8%
accuracy for Gujarat state.
•Rainfall predictions made by other astro-
meteorologists for Gujarat were also validated.
The average Y/N skill score was 55.5%, 66.1%,
67.3% and 65.9% for DhansukhShah, Sudhakar
Joshi, PravinbhaiVora
and H.S. Nimavat
respectively for June to October, 2007.
However, other workers have predicted
rainfall region wise
(Saurashtra, south
Gujarat, north Gujarat, middle Gujarat
etc.) or state as a whole, while, AAU’s
almanac made predictions district wise on
daily basis.Thus, AAU’s almanac had fine
grid (≈ 1 district) and more accuracy.
Validation of rainfall projection for four regions of
Gujarat.
39.6
33.4
4.6
845.2
1179.8
1127.4
State
97.9
32.3
49.6
579.4
1146.7
766.6
Saurashtra
4
13.6
48.2
-37.6
1420.9
1613.8
2105.5
South
Gujarat
3
66.4
21.1
37.4
583.8
971.2
706.7
North
Gujarat
2
24.0
16.8
6.1
796.6
987.5
930.7
Middle
Gujarat
1
Actual
Rainfall
(% Dep.
From
norm
al)
Rainfall
Projecti
on (%
Dep.
From
norm
al)
Rainfall
Projecti
on (%
Dep.
From
actual)
Norm
al
Rainfall
(mm)
Actual
Rainfall
(mm)
Rainfall
Projection
(mm)
Region
Sr.
No
The rainfall projection for the state as a whole
was quite good with +4.6% departure from actual
rainfall which was less than 10% (i.e. 95.4%
accuracy).
For Middle Gujarat also departure was +6.1%
from actual rainfall. The actual rainfall was above
norm
al for all zones of Gujarat and state rainfall
was 39.6% higher than normal whereas our
projections were also showing above norm
al
rainfall for all zones.
Our projection for the state as a whole was
33.4%
higher than norm
al, which gave correct
trend of above norm
al prediction in M
onsoon 2007.
Acknowledgem
ent
The
astrolo
gic
al m
ethodolo
gy o
f ra
infa
ll
pre
dic
tion w
as p
repar
ed a
nd u
sed for
Guja
rat stat
e w
as d
evel
oped
by a
tea
m o
f
the
astrolo
gists n
amel
y, Shri. Lax
mik
ant
Chim
ote
, M
rs. N
ilim
aChim
ote
and S
hri.
Ked
arD
amle
from
Dom
biv
ali(M
S).
The
auth
ors
ack
now
ledge
thei
r hel
p in
pre
par
ing a
stro
logic
al fore
castin
g o
f distric
t
wise
rain
fall.
THANK YOU