Cloud Seeding for Drought Mitigation in Telangana and Rayalaseema

1. Experience of Cloud Seeding Operations for Mitigation of Drought Conditions in Telangana and Rayalaseema CENTRE FOR WATER RESOURCES Institute of Science and Technology JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY E- mail: cwr_jntu@yahoo.com coordinatorcas@gmail.com Dr. B.Venkateswara Rao Prof.Water Resources

2. 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.

3. 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.

4. Rain Shadow Area Development Department • 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 . • 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. • Most of the RS Mandals are lying in the districts of Ranga Reddy, Nalgonda, Mahbubnagar, Guntur, Prakasam, Nellore, Kurnool, Anantapur, Cuddapah and Chittore districts. • Districts like Chittore, Nellore, Prakasam, and Guntur receive rainfall during northeast monsoon also. • 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. • 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

5. History of cloud seeding operations in Andhra Pradesh

6. 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.

10. 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% - China Present 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

11. 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

13. 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)

14. 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

15. Testing of flare Particles producing Cloud condensation nuclei (CCN), its size distribution over ground

17. Weather charts used for weather forecast

18. RADAR Image showing seeding of cloud Seeded Cloud Flight track TITAN DISPLAY

23. Control Cloud 137 Control Cloud 133 Control Cloud 134 Target Cloud 136/147

28. Seeding of Target Cloud 136/147