cloud seeding presentation
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Experience of Cloud Seeding Operations for Mitigation of Drought Conditions in Telangana
and Rayalaseema
CENTRE FOR WATER RESOURCES
Institute of Science and TechnologyJAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY
E- mail: cwr_jntu@yahoo.comcoordinatorcas@gmail.com
Dr. B.Venkateswara Rao Prof.Water Resources
Initial cloud seeding experiments
•In the late 1940‘s Langmuir and his Colleagues at the general electric research laboratory discovered that dry ice when dropped into a supercooled cloud deck from an airplane, caused a rapid conversion of water to ice leading quickly to the production of snowflakes and dissipation of cloud in the region seeded.
•Soon they discovered that silver iodide had same nucleating property
•Another method for stimulating the precipitation has been found by injecting salt particles near the base of the cloud to provide centres for droplet formations. After these discoveries many experiments have been carried out all over the world.
•Today more than 25 countries around the globe are under taking cloud seeding including America, Russia, china, south Africa, Australia, Canada, Israel, Jordan, newzeland, UAE, Argentina,Thailand etc.
Indian History of cloud seeding
•1951- Tata firm over western Ghats using ground based silver iodide generators
•1957-1966 National Physical Laboratory (NPL) conducted experiments using ground based generators, in North India.
•1973-1974, 1976 and 1979-86 IITM, experiments with cloud seeding shows 24% increase in the rain fall
•1983, 1984-87, 1993-94 Tamil Nadu Govt carried out cloud seeding•1990-2000 witnessed many advances in the airborne instrumentation, radars, flares and softwares.They got
imported to India in new millennium.•2003 Karnataka Govt. has initiated cloud seeding with modern gadztes like radars and aircrafts Maharashtra Govt. followed a month later.•2003-2009 Andhrapradesh Govt. has conducted cloud seeding operations perhaps the longest & biggest programme in south east Asia.
o Government of Andhra Pradesh has declared 555mandals out of 1125mandals as Rain Shadow Areas through their Memo. No. 180/RS.V/2004-I; 22nd July 2005.This comprises an area of 1,35,680 Sq.km out of total area of 2,75,045 Sq. km .o The classification of Rain Shadow (RS) Mandals was done based on the mandal receiving less than 600mm rainfall during Southwest monsoon period in
9years out of last 18years. o Most of the RS Mandals are lying in the districts of Ranga Reddy, Nalgonda,
Mahbubnagar, Guntur, Prakasam, Nellore, Kurnool, Anantapur, Cuddapah and Chittore districts.
o Districts like Chittore, Nellore, Prakasam, and Guntur receive rainfall during northeast monsoon also.
o In order to enhance rainfall, dynamic seeding of clouds was taken-up in the above RS districts during both Southwest and Northeast monsoons,
with the instructions of Hon’ble Chief Minister of Andhra Pradesh Dr Y.S.Rajasekhara Reddy, under the Project, called INDIRA MEGHAMADHANAMU, which was started in the year 2004. o These programmes are regularly being monitored by Hon’ble Minister for
Agriculture, Sri N.Raghuveera Reddy and Principle Secretary of Rain Shadow Area Development (RSAD) Department. In addition to the state level
committee and technical committee comprises several experts in the field
Rain Shadow Area Development Department
Year Operating Agency Monitoring AgencyNo. of Flares % of
SuccessNo of
Mandals Covered in
656 Mandals
No. of C-Band Radars Hygros BIP Eject
ables
2003
Weather Modification Incorporation (WMI) of Fargo, USA in association with AGNI Aviation, Bangalore.
WALAMTARI, Government of Andhra Pradesh.
121 69 582
63WEATHER RADAR,at Jekkur Aerodrome near Bangalore.
2004
Weather Modification Incorporation (WMI) of Fargo, USA in association with M/s AGNI Aviation, Bangalore.
PanchayathRaj Department; Government of AP.
963 161 1436 59.6 510
Weather Radars were installed at Karimnagar and Nandyal.At the time of withdrawal of Southwest monsoon, Karimnagar Radar was shifted to Tirupathi to study Northeast monsoon clouds.
2005 M/s Agni Aviation, Bangalore.Jawaharlal Nehru Technological University (JNTU),Hyderabad.
457 52 185 71.7 476C-band Radars at Ibrahimpatnam and Anathapur.
2006 M/s Agni Aviation, Bangalore.Jawaharlal Nehru Technological University (JNTU), Hyderabad.
200 27 15 54.4 552Ibrahimpatnam Radar was shifted to JNTU, Kukatpally and with the other Radar at Anathapur.
2007 M/s Agni Aviation, Bangalore.Jawaharlal Nehru Technological University (JNTU), Hyderabad.
547 82 -- 82 566JNTU, Kukatpally, Hyderabad and other Radar at Anathapur.
2008M/s Agni Aviation, Bangalore. Jawaharlal Nehru
Technological University (JNTU), Hyderabad.
563 * -- --78.2 651 JNTU, Kukatpally, Hyderabad
and other Radar at Anathapur
2009 M/s Agni Aviation, Bangalore. Jawaharlal Nehru Technological University (JNTU), Hyderabad
541 -- -- 75.7 558 JNTU, Hyderabad, Anathapur and Tirupati
History of cloud seeding operations in Andhra Pradesh
Philosophy behind Cloud Seeding
•Thirteenth world meteorological congress in May 1999 noted that the weather modification for rainfall enhancement is the one of the tools in the total gamut of water resources management.•In the Indian context it is well established fact that even if we achieve ultimate irrigation potential we can irrigate only 30% of cultivable land, remaining 70% is under rain fed conditions where erratic and low rainfall is the problem.•Research shows that even the watershed management activities in the rainfed agriculture may not yield good results if the rainfall deficiency is more than 20%.•We are declaring agricultural drought if the rainfall deficiency is 25% and above. •If the cloud seeding programme could cover the above deficiency rainfall it is worth taking.
Geographical area of the country :322 M.ha about 60% of total area 10%-USSR
Cultivable Area : 188 M.ha 29%-U.K. 20% - U.S
Cropped land at present :144 M.ha 26% - Pak.
10% - ChinaPresent area under irrigation : 78 M.ha
Likely irrigated area by the year 2025to meet food production :100 M.ha
Total utilisable Water Resources :114 M.ha.m
Present utilisation : 55 M,ha.m
Water required by the year 2025 : 105 M.ha.m
Present population of the country : 1000 million
Population by the year 2025 : 1290 million
Present total food production of the Country : 200 M.tonnes
Required food production by the year 2025 : 350 M.tonnes
Present food consumption per capita per day : 580gms
Average food production at present : 2.2 t/ Ha for irrigated land and
0.75t/Ha for un
irrigated land Average food production required by the year 2025assuring with more than 70% of the cropped area will be irrigated : 3 t/Ha
Rain Drop
(This is not exact composition of a rain Drop)Average raindrop size is about 2-3 mm
(Raindrop has a small impurity In the middle)
PARTICLE SIZE NATURAL vs FLARE
S.No
HYDERABAD ANANTHAPUR FLARE
Particles Size (Microns)
% of Total
Particles Size (Microns)
% of Total
Particles Size (Microns)
% of Total
1 0.2 41.60% 0.1 41.60% 0.8 28.50%
2 0.4 33.30% 0.3 33.30% 1 12.50%
3 0.6 16.60% 0.5 16.60% 0.2 14.60%
4 0.8 8.30% 0.7 8.30% 0.4 10.20%
• Minimum Diameter of the Rain Drop to fall as rain due to gravity is 0.5mm
• To form this rain drop and to a bigger size the appropriate Cloud Condensation Nuclei (CCN) size required is
1-3microns
Testing of flare Particles producing Cloud condensation nuclei (CCN), its size distribution over ground
Weather charts used for weather forecast
RADAR Image showing seeding of cloud
Flight track
Seeded Cloud
TITAN DISPLAY
Control Cloud 137
Target Cloud 136/147
Control Cloud 134
Control Cloud 133
Seeding of Target Cloud 136/147
Post seeding Pilot Log
Seeding Altitudes over the years 2005-2008.
Updrafts observed at the cloud base over the years 2005-2008
25 Aug 09 seeding locations and Post seeding cloud trackFirst time seeding influence is evaluated by considering zone of influence only under the
seeded cloud.
25 Aug 09 seeding locations and Spatial distribution of rain gauge recorded rainfalls (mm) & Rainfalls below the seeded cloud track.
Post seeding rainfall verification over phone with farmers and administrative people
Date Name of the Seeding Mandal District Designation Phone Number Status Remarks
6-Nov-09 Owk Kurnool Adarsha Rythu 9440915099 Drizzled at seeded village
6-Nov-09 Peddavadguru Ananthapur M.A.O 9490597714 Rainfall confirmed at seeded village
6-Nov-09 Yellanur Ananthapur M.A.O 9985754095 Rainfall confirmed at seeded village
7-Nov-09 Beluguppa Ananthapur Adarsha Rythu 9177029513 Drizzled at seeded village
7-Nov-09 Kanekal Ananthapur Adarsha Rythu 9951292526 Rainfall confirmed at seeded village
7-Nov-09 Gooty Ananthapur Asst.Geologist A.P Mines 9704197760 Drizzled at seeded village
7-Nov-09 Gummagatta Ananthapur Adarsha Rythu 9492328773 Drizzled at seeded village
7-Nov-09 Peddavadguru Ananthapur M.A.O 9490597714 Drizzled at seeded village
11-Nov-09 Talapula Ananthapur M.A.O 9490597760 Rainfall confirmed at seeded village
11-Nov-09 Simhadripuram Kadapa M.R.O 9959667440 Rainfall confirmed at seeded village
17-Nov-09 Tanakal Ananthapur M.A.O 9490597762 Rainfall confirmed at seeded village
17-Nov-09 Badvel Kadapa M.A.O 9573656243 Drizzled at seeded village
17-Nov-09 Gopavaram Kadapa Adarsha Rythu 9441519891 Drizzled at seeded village
17-Nov-09 Sambepalli Kadapa Adarsha Rythu 9000298920 Rainfall confirmed at seeded village
17-Nov-09 Pendlymarri Kadapa Adarsha Rythu 9959216491 No Rain at seeded village
20-Nov-09 Gorantla Ananthapur M.A.O 9490597748 Rainfall confirmed at seeded village
20-Nov-09 Parigi Ananthapur M.A.O 9490597745 Rainfall confirmed at seeded village
20-Nov-09 Putlur Ananthapur M.A.O 9490597707 Rainfall confirmed at seeded village
20-Nov-09 Kondapuram Kadapa Adarsha Rythu 9440136052 Drizzled at seeded village
20-Nov-09 Simhadripuram Kadapa Adarsha Rythu 9912501709 Drizzled at seeded village
20-Nov-09 Chilamathuru Ananthapur M.A.O 9490597747 Rainfall confirmed at seeded village
21-Nov-09 Obuladivaricheruvu Ananthapur M.A.O 9490597749 No Rain at seeded village
21-Nov-09 Amadgur Ananthapur M.A.O 9490597749 No Rain
21-Nov-09 Ramgiri Ananthapur M.A.O 9490597725 Rainfall confirmed at seeded village
21-Nov-09 Kambadur Ananthapur M.A.O 9490597714 Drizzled at beside seeded village
8day (09 Oct – 16 Oct 2009) Enhanced vegetation Index (EVI) map 8day (12 Dec – 19 Dec 2009) Enhanced vegetation Index (EVI) map
8day Enhanced vegetation Index (EVI) maps derived from MODIS (TERRA/AQUA)
TITAN Software•TITAN means Thunder storm Identification Tracking Analysis and Now-casting
•It is a software developed for forecasting and analysis of thunder storms in weather modification programs
•TITAN gives 10 derived parameters of the cloud giving a scope to find latitude and longitude and cross sectional view of the clouds at any instant.
•The cloud parameters given by the TITAN are given as Area, Volume, Mass, Precipitation Flux, Vertical Integrated Liquid Content etc.,
1) Area (km2) : Area (km2) covered by the cloud, it is the value of horizontal spread up of the cloud as observed by radar
2) Volume (km3) : Volume (km3) of the cloud, it is the value of the volume occupied by the cloud as observed by radar
3) Mass (k tons) : Mass (k tons) of the cloud, it is the value of the mass contained by the cloud as observed by radar
4) V I L (kg/m2) : Vertical Integrated Liquid content (kg/m2) of the cloud, it is the value of the vertical integration of liquid matter present in the cloud as observed by the radar
5) P-flux (m3/sec) : Precipitation flux of the cloud, it is the value of the flux of mass ( Precipitation) falling down from the cloud as observed by the radar
6) Max- Z (dbz) : Maximum reflection of the cloud, it is the value of the maximum reflection of the cloud as observed by the radar. Reflection depends on the type of the matter present in the cloud, basically if the matter if the matter present in the cloud is more, the reflection of the cloud will be more
7) Ht-maxZ (km) : Height of maximum reflection of the cloud, it is the value of the height from which maximum reflection is coming from the cloud as observed by the radar.
8) Centroid (km) : Centroid of the cloud is basically known as the centre of gravity of the cloud, it is the height at which the total weight of the cloud is said to be concentrated as observed by the radar
9) Cloud Base (km) : Cloud Base is the height of the bottom part of the cloud from the earths surface as observed by the radar
10) Cloud Top (km): Cloud Top is the height of the top most part of the cloud from the earths surface as observed by the radar
Target and Control Method•By using TITAN software we can compare various parameters of Seeded and Unseeded clouds which is known as “Target and Control method”•In the Target and Control method Target means the Seeded cloud and the Control means the Unseeded cloud.
Control Cloud 137
Target Cloud 136/147
Control Cloud 134
Control Cloud 133
Seeding Aircraft
Seeding of Target Cloud 136/147
Target Cloud
11 Aug 2008 Target & Control Rainfall Analysis
Target cloud trackControl cloud track
Track no.133
Track no.134
Track no.136- 136/147
Distance traveled= 128 Km Life span= 1.29 Hours
Distance traveled= 82 KmLife span= 1.07 Hours
Distance traveled= 91 KmLife span= 2.41 Hours
Seeding Location18,500ft (500mb) WNW/15 Kt
14,500ft (600mb) WNW/20 Kt
10,000ft (700mb) W/35 Kt
5,000ft (850mb) W/40 Kt
N
Seeding Altitude (Ft)
Seeding Altitude (m)
Up Draft in (Ft/Min)
Up Draft in (m/s)
Up Draft in Knots
4500 1350 300 1.5 2.9
Control Clouds
Track no.137
Variation of Volume of Seeded and Unseeded clouds on August 11, 2008
0
50
100
150
200
-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
Time [minutes] *0minutes is the seeding time
Volu
me
[ k
m3
]SeededVolume UnseededVolume
Variation of Area of Seeded and Unseeded clouds on August 11, 2008
0
25
50
75
-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
Time [minutes] *0minutes is the seeding time
Area
[
km2
]
Seeded Area Unseeded Area
Variation of Mass of Seeded and Unseeded clouds on August 11, 2008
0
25
50
75
-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
Time [minutes] *0minutes is the seeding time
Mas
s [k
.tons
]Seeded Mass Unseeded Mass
Variation of VIL of Seeded and Unseeded clouds on August 11, 2008
0
1
2
3
4
-35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
Time [minutes] *0minutes is the seeding time
V.I.L
. [ k
g / m
2 ]
Seeded VIL Unseeded VIL
DOUBLE RATIO METHOD
•It is the ratio of two ratios•The numerator is the ratio of total rainfall of Target area [S] to the total rainfall of Control area [NS] during seeding days [ S/NS]•The denominator is the ratio of total rainfall of the Target area [H] to the total rainfall of Control area [K] during 10 unseeded years. [H/K]•Reference: Dr.Ali Umran Komuscu, Turkey, Journal of Weather Modification, Volume 40,April 2008, Page No. 17-27.
Where • IC = Impact Coefficient• S = Total rainfall in the target area during seeding period • NS = Total rainfall in the control area during seeding period • H = Total rainfall in the targeted area during 10unseeded years • K= Total rainfall in the control area during 10unseeded years• [ I.C >1 indicates influence of seeding ]
]/[]/[.
KHNSSCI
Correlation between Rain fall of Target and Rain fall of Control stations during 10 unseeded years
(1990-2000)
Target/Control Anantapur Target/ Control Mahaboobnagar
Kadapa 0.67 Medak 0.54
Chittoor 0.69 Nalgonda 0.78
Kurnool 0.88 Kurnool 0.72
Target/Control Nalgonda Target/Control Ranga Reddy
Medak 0.45 Medak 0.78
Ranga Reddy 0.6 Mahaboobnagar 0.83
Mahaboobnagar 0.78 Nalgonda 0.6
NALGONDA vs. CONTROL stations ComparisonCorrelations coefficients
Target /Control stations Mahaboobnagar Ranga Reddy MedakNalgonda 0.78 0.6 0.45
Impact Coefficients 2009 for 15 Days of Cloud Seeding operations a = S/NS b = H/K I.C= a/ b Change %
Nalgonda vs. Mahaboobnagar 0.72 1.07 0.67 No Change
Nalgonda vs. RangaReddy 1.37 0.85 1.61 61Nalgonda vs. Medak 1.13 0.83 1.83 36
Impact Coefficients 2008 for 17 Days of Cloud Seeding operations a = S/NS b = H/K I.C= a/ b Change %
Nalgonda vs. Mahaboobnagar 1.68 1.07 1.57 57Nalgonda vs. RangaReddy 1.61 0.85 1.89 89
Nalgonda vs. Medak 1.52 0.83 1.83 83Impact Coefficients 2007 for 21 Days of Cloud Seeding operations
a = H/K b= S/NS I.C= b/a Change %Nalgonda vs. Mahaboobnagar 1.41 1.07 1.32 32
Nalgonda vs. RangaReddy 1.18 0.85 1.39 39Nalgonda vs. Medak 1.84 0.83 2.22 122
R a i n M a s s o f 3 0 S e e d e d a n d 3 0 U n s e e d e d c l o u d s - H y d e r a b a d 0 8
0
1 0 0
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
7 0 0
5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 0 6 5T i m e [ m i n u t e s ]
Ra
in M
as
s [
kto
ns
]
S e e d e d R M H y d 0 8U n s e e d e d R m H y d 0 8
R a i n M a s s o f 2 7 S e e d e d a n d 3 0 U n s e e d e d c l o u d s - A n a n t a p u r 0 8
0
1 0 0
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
7 0 0
8 0 0
5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 0 6 5
T i m e [ m i n u t e s ]
Ra
in M
as
s [
kto
ns
]
S e e d e d R M A T P 0 8U n s e e d e d R M A T P 0 8
Temporal Variation of Rain Mass with different data sets
Weekly CUMULATIVE RAINFALL STATUS for the year-2009
Week EXCESS NORMAL DEFICIENT SCANTY No Rain TOTAL MANDALS
ANDHRA RSAD % in
RSAD ANDHRA RSAD % in
RSAD ANDHRA RSAD % in RSADANDHRA RSAD % in RSADANDHRA RSAD % in RSAD ANDHRA RSAD
01 JUN-10 JUN 2009 195 132 67.69 124 72 58.06 217 115 53.00 326 180 55.21 242 154 63.64 1104 653
01 JUN-17 JUN 2009 153 146 95.42 163 121 74.23 263 176 66.92 466 188 40.34 59 22 37.29 1104 653
01 JUN-24 JUN 2009 157 152 96.82 161 136 84.47 294 180 61.22 461 173 37.53 31 12 38.71 1104 653
01 JUN-01 JUL 2009 159 128 80.50 197 129 65.48 374 222 59.36 363 168 46.28 11 6 54.55 1104 653
01 JUN-08 JUL 2009 108 75 69.44 212 115 54.25 504 283 56.15 278 178 64.03 2 2 100.00 1104 653
01 JUN-15 JUL 2009 87 36 41.38 219 107 48.86 537 318 59.22 261 190 72.80 0 2 0.00 1104 653
01 JUN-22 JUL 2009 51 14 27.45 187 86 45.99 568 308 54.23 298 245 82.21 0 0 0.00 1104 653
01 JUN-29 JUL 2009 27 13 48.15 118 44 37.29 536 280 52.24 423 316 74.70 0 0 0.00 1104 653
01 JUN-05 AUG 2009 22 5 22.73 111 37 33.33 494 265 53.64 477 346 72.54 0 0 0.00 1104 653
01 JUN-12 AUG 2009 17 3 17.65 79 20 25.32 459 251 54.68 549 379 69.03 0 0 0.00 1104 653
01 JUN-19 AUG 2009 21 12 57.14 132 70 53.03 556 349 62.77 395 222 56.20 0 0 0.00 1104 653
01 JUN-26 AUG 2009 42 31 73.81 207 140 67.63 670 381 56.87 185 101 54.59 0 0 0.00 1104 653
01 JUN-02 SEP 2009 80 68 85.00 291 215 73.88 662 332 50.15 71 38 53.52 0 0 0.00 1104 653
01 JUN-09 SEP 2009 56 51 91.07 310 222 71.61 673 340 50.52 65 40 61.54 0 0 0.00 1104 653
01 JUN-16 SEP 2009 66 58 87.88 303 223 73.60 667 332 49.78 68 40 58.82 0 0 0.00 1104 653
01 JUN-23 SEP 2009 60 58 96.67 283 207 73.14 688 341 49.56 73 47 64.38 0 0 0.00 1104 653
01 JUN-30 SEP 2009 92 86 93.48 345 254 73.62 621 285 45.89 46 28 60.87 0 0 0.00 1104 653
01 Jun- 07 Oct 2009 122 115 94.26 346 233 67.34 614 286 46.58 22 19 86.36 0 0 0.00 1104 653
01 Jun- 14 Oct 2009 107 104 97.20 305 211 69.18 672 321 47.77 20 17 85.00 0 0 0.00 1104 653
01 Jun- 21 Oct 2009 96 95 98.96 273 193 70.70 696 339 48.71 39 26 66.67 0 0 0.00 1104 653
01 Jun- 28 Oct 2009 90 89 98.89 253 178 70.36 709 357 50.35 52 29 55.77 0 0 0.00 1104 653
01 Jun- 04 Nov 2009 83 82 98.80 236 165 69.92 717 358 49.93 68 48 70.59 0 0 0.00 1104 653
01 Jun- 11 Nov 2009 96 95 98.96 298 228 76.51 676 312 46.15 34 18 52.94 0 0 0.00 1104 653
01 Jun- 18 Nov 2009 86 85 98.84 321 242 75.39 672 310 46.13 25 16 64.00 0 0 0.00 1104 653
01 Jun – 25 Nov 2009 92 88 95.65 352 259 73.58 647 298 46.06 13 8 61.54 0 0 0.00 1104 653
Pre and Post seeding weeks
20 Jul – 23 Nov 2009Total No.of seedings = 541 01Jun – 23 Nov 2009
Seeding Locations Rainfall Status
Upto Seeding Period
23 Jul – 23 Sep 2009Total No.of seedings = 339 01Jun – 23 Sep 2009
Seeding Locations Rainfall Status
Before October Flood
NO.OF EXCESS MANDALS=808NO.OF NORMAL MANDALS =265NO.OF DEFICIENT MANDALS =32NO.OF SCANTY MANDALS =00No.of No Rain Mandals =00
NO.OF EXCESS MANDALS= 173NO.OF NORMAL MANDALS = 589NO.OF DEFICIENT MANDALS =335NO.OF SCANTY MANDALS = 08No.of No Rain Mandals = 0
Spatial distribution of Seasonal Rainfall in the Years 2010 and 2011 (as on 15th Sep)
20102011
0
100
200
300
400
500
600
700
800
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Average annual monsoon rainfall
3 yrs. Moving Average annual monsoon rainfall
0
100
200
300
400
500
600
700
800
900
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Average annual monsoon rainfall
3 yrs. Moving Average annual monsoon rainfall
Nalgonda seeded
Nalgonda unseeded
Long term rainfall analysis during monsoon between seeded and unseeded areas in the Nalgonda district, A.P
year
Rai
nfal
l
year
Rai
nfal
l
Appearance of Seedable Clouds [>30min] over Hyderabad RADAR from 20th July to 07 August, during the years 2007,2008 & 2009
189
120
62
020406080
100120140160180200
TOTAL
No
of C
loud
s
2007Year 2008 Year 2009 Year
S.No Year No of Aircraft
s used
No of RADAR
sUsed
Total districts covered
No of
Mandals
seeded
% of Rainfall
attributed
to cloud seeding
operations
No. of water
samples analyzed
CostIn
Crores
1 2003 1 0 1 63 -- -- --2 2004 3 2 16 510 -- 14 10.673 2005 3 2 10 476 12.85 108 20.634 2006 2 2 10 552 17.25 610 14.245 2007 2 2 12 566 19.17 2159 22.376 2008 2 2 12 651 18.25 942 24.97 2009 3 2 12 558 17.01 536 25.40
Summary of cloud seeding operations over Andhra Pradesh (2004 – 2009)
•Cloud seeding water cast = 3 paise per Cu.m
• Warm cloud seeding is more effective in the last four years• Cloud Seeding is effective on Continental clouds over Anathapur,
Cuddapah, Kurnool, Mahbubnagar, Nalgonda and Ranga Reddy districts where seeding particle size suits for the enhancement of Clouds after seeding. • Cloud Seeding is ineffective on maritime clouds over coastal districts of Guntur, Prakasam, Nellore and eastern half of Chittore. • Probably the size of seeded particle is smaller than Salt particles found in this atmosphere. Hence instead of forming into a rain drop, more droplets have formed and dissipated. Therefore different increased size CCN is required for maritime clouds.• It is also observed in general that cloud seeding is more effective if we get bigger size monsoon clouds and it is less effective if we get smaller size monsoon clouds.• Of late 0.5kg flares with 3 to 4 micron size is observed to be yielding good results.
Lessons learnt:
Thank
you……….
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