The Karnataka government led by Chief Minister BS Yeddyurappa is continuing the cloud-seeding project that was approved by former CM Kumaraswamy’s cabinet, despite the heavy rains and floods that have lashed the state since then.
Cloud seeding is a weather-modification experiment to induce rainfall from rain-bearing clouds using chemicals. For Karnataka, flares of sodium chloride and potassium chloride is being used to trigger hygroscopic cloud seeding.
Though rains recently lashed many parts of the state this month, cloud seeding is being carried out due to low soil moisture levels in many taluks of the state even after floods forced people of 13 districts to be shifted to relief camps. According to an earth scientist, this strange situation has led the government to declare both flood and drought at the same time. They said that riverine flooding meant that groundwater was not recharged much as it would have if water percolated due to days of continuous rain.
“Districts like Vijaypura, Yadgir, Raichur, Koppal, Kolar, Chikkaballapura and Bengaluru Rural have very low soil moisture, which makes them unfit for agriculture,” said Prakash, the chief engineer of Rural Drinking Water and Sanitation of the Karnataka Rural Development Department and who is associated with the cloud seeding program.
“For obvious reasons, we have not done it in areas which flooded. The criteria to pick targets depends on two factors — soil aridity and the availability of rain-bearing clouds. We also take the rainfall in the last few days into account. The data on soil moisture and cloud density is assessed by meteorologists and based on that, we plan the day. Initially, the plan was to deploy one plane in Hubbali and one in Mysuru. But since there was good rain in south Karnataka, we moved both the planes to Hubbali,” Prakash explained.
The aridity could possibly be because Karnataka was affected by drought for 12 out of the last 18 years.
Even currently, six districts of Karnataka have deficient yearly rainfall. The recent floods claimed at least 88 lives and forced close to 16 lakh people to move to relief camps.
When one sees district-wise, Kalaburagi in the Hyderabad-Karnataka region has the worst rainfall and has a 40% deficiency. In the coast, Dakshina Kannada has a deficit of 21% annual rainfall to date.
While all major reservoirs in the state are filled to the brim, the status of the minor irrigation (MI) tanks across the state show a more dire picture, as only 40% of the state is serviced by irrigation projects.
According to KSNDMC data, all minor irrigation tanks in Bidar and Yadgir are dry. Districts like Vijayapura, Kalaburagi, Bagalkote, Ballari, Davanagere, Chitradurga, Tumakuru, Chikkaballapur, Kolar, Mandya and Chamarajanagar also have an overwhelming number of empty tanks.
Officials in the know said that intra-district variations in rainfall at the taluk or hobli level is also high, which affects the soil potency to grow crops.
The state government previously carried out cloud seeding in 2017, which saw considerable success. Following that, experts from the Indian Institute of Science, Indian Institute of Tropical Meteorology in Pune, National Aerospace Laboratories and the Indian Meteorology Department suggested that the Karnataka government carry out this exercise every year.
Officials also said that clauses of the existing contact meant the project can be carried for 90 days starting from July-end, with a maximum of 200 hours of flight time for each of the two aircraft. “The only variable is the amount of chemicals burnt, that we have to pay in actuals,” Prakash said.
According to him, the project has shown notable success even though official statistics can only be presented at a later time.
“In every area that we attempted, there has been a minimum of 5-30 mm of rainfall. In 2017, a detailed evaluation took a good six months to prepare. We will soon make the data with preliminary findings public," he said.