With a severe water crisis looming large in Mumbai -- thecommercial capital of India and neighbouring Thane and Raigad districts -- theBrihan Mumbai Municipal Corporation (BMC) is contemplating carrying outartificial rain through cloud seeding.
The situation in the Mumbai Metropolitan Region (MMR) -- andcivic bodies like BMC, Thane Municipal Corporation, Navi Mumbai MuncipalCorporation, Vasai-Virar Municipal Corporation are resorting to water cuts.
The BMC is contemplating approaching Mekorot, an Israelinational water company, to help it carry out cloud seeding in six reservoirs.
But the expert, Shantilal N Meckoni said that itcannot be done in haste.
The lakes that supply drinking water to Mumbai are “ Bhatsa,Upper Vaitarna, Modak Sagar, Tansa, Vihar and Tulsi -- majority of them are inthe neighbouring Thane district.
“We need to plan it properly....it cannot be done in haste.To do cloud seeding in July and August, you have to plan from April-May.....,”Meckoni, who heads the Meckoni Exterprises, said. He pointed out that there wasalso need for better coordination among the BMC and the India MeteorologicalDepartment (IMD) -- to make such experiments successful.
Besides successfully conducting cloud seeding in Thane, hehas also done it in Kutch region, Hyderabad and in some places at Tamil Nadu.In Maharashtra, he has conducted cloud seeding in Ojhar near Nashik and Sangliin 1994-95.
Explaining the concept of cloud seeding and its history in India, he said thatthe concept first started in Kutch, the region from where he hails. “In 1989,the rainfall in Kutch was not okay. I happened to meet a farmer from Israel,who came out with the idea of trying cloud seeding there,” he said, adding thatwith the help of authorities of IMD and its cyclone detection centre at Kutch,the experiment was conducted. “In 14 sites of the 28 selected, we could haverains in a 100 km belt. The average was nearly 75 mm,” he said.
Subsequently, in 1992, the BMC officials got in touch with Meckoni and theyconducted it over Vaitarna and Tansa lakes.
As far as the process is concerned, he said that in a furnace, first coal isburnt at 1,350 degree C on which silver iodide (which is in powdered form) issprinkled. “After it fuses, the particles being lighter than air travels up,”he said, adding that in 10 to 12 minutes it reaches cloud concentration. Thereare certain parameters as well “ the cloud are to be at the height of 8,000 to10,000 metres.
Once these particles travel up, it crystallizes at (minus) “ 5 degree C.“Clouds have ice crystals and water. “These particles attract the water andwhen the weight increases, it comes down in form of rain,” he said, adding thatin one to one-and-a-half-hour rains should start. “In Israel and US, aircraftare used, where the silver iodide is heated through tungsten wires,” he added.Another precursor for the process is that the wind speed must be in the rangeof 15 to 20 kmph, else the clouds will blow away from the area when the rainsare desired “ and the humidity must be over 70 per cent.
As far as the cost is concerned, Meckoni said that it should work out fornearly Rs 1 lakh per day and on a day we can achieve nearly 30 to 35 mm averagerain “ provided the parameters are met.
“First we introduced a 10 per cent water cut across someparts of the city then followed it up to almost 25 per cent in central andwestern suburbs but even that has not helped in maintaining the water levels inthese scarce rains,” Municipal Commissioner Sitaram Kunte, said.
The BMC on these lines has now begun the tender process toappoint an agency to carry out cloud seeding and has sought permission for theprocedure from the central government. It has also asked the Indian Instituteof Technology (IIT) to provide technical support on the feasibility of cloudseeding.
“We have drafted a letter asking IIT to help us in our efforts,” Kuntesaid.
