Cloud seeding could become an annual fixture in Karnataka as the government is seriously considering a report by a team of scientists that gave a thumbs-up to last year’s experiment.
An evaluation team comprising scientists, which submitted its report on the Rs 34-crore Varshadhaare cloud seeding project that was done last year, has recommended that cloud seeding be done every year, Rural Development and Panchayat Raj (RDPR) Minister Krishna Byre Gowda told DH.
“The experts got back to us with a positive feedback,” Gowda said. “The cost-benefit ratio was 1:2, excluding crops. The team measured the impact cloud seeding had on drinking water and apparently, the benefit was twice the effort that we put in.”
Cloud seeding involves spreading aerosol (silver iodide or sodium chloride) into the clouds to stimulate the precipitation process and form rains. The proposal for yearly cloud seeding will be placed before the Cabinet soon, Gowda said.
The government dropped its plans to carry out cloud seeding this year for some regions in north Karnataka as it was too late. “The minimum preparation time for cloud seeding is three months. Clouds with dense moisture last only till September with only 20% of rain-bearing clouds available at this time of the year,” Gowda said.
Authorities will be asked to start preparing early for next year’s cloud seeding. “Tendering itself will take about a month and arranging the aircraft another two months,” the minister said.
Last year, cloud seeding was done between August 21 and November 10. In this period, two aircraft flew for 286.51 hours and burnt 1,302 flares into clouds in the Cauvery, Malaprabha and Tungabhadra river basins.
The evaluation team - experts from IISc, Indian Institute of Tropical Meteorology in Pune, NAL and the Indian Meteorology Department were part of it - concluded that the Varshadhaare project generated 2.51 tmc of additional water. Rainfall generated was 27.9% above the natural rainfall, the team said in its report. The report has recommended setting up a permanent body to carry out cloud seeding, besides formulating a long-term cloud seeding policy.
Before Varshadhaare, cloud seeding was done last in 2003 under the S M Krishna regime. In July 2008, former RDPR minister H K Patil arranged cloud seeding as a private initiative in Gadag, Haveri and Dharwad districts, which he claimed resulted in rainfall. “We’re also planning to organise an international conference so that we collectively arrive at a scientific consensus on cloud seeding,” Gowda said.