The northeast (NE) monsoon has been unfavourable to Bengaluru this year. The city received only 72 mm of rain in the October-November period, as against the excessive 202 mm during the same period last year.
Experts fear it could result in ground water depletion and soaring temperatures. Even the SW monsoon was short by 9% in Bengaluru. As per data from the Karnataka State Natural Disaster Monitoring Centre (KSNDMC), the NE monsoon was short by 69% between October and November. The figure is a matter of concern, given that the SW monsoon was also short by 77mm. “The city received 746 mm between January and October compared with 823 mm during the same period last year,” said KSNDMC director GS Srinivasa Reddy.
The city receives 70% of its annual rainfall during the SW monsoon, which normally ends in September. A smaller-yet-crucial 30% of its rainfall occurs during the NE monsoon season between October and May. “As the catchment area of river Cauvery has received good rains this year, there will be no problem of supplying water to the city,” BWSSB chairman Tushar Girinath said. “The shortfall of rain could, however, increase dependency on Cauvery water in case the bore-wells go dry,” he said.
Experts note that neglecting groundwater recharging could cause serious problems in future. “There is hardly any provision in the city for groundwater recharging could cause serious problems in future. “There is hardly any provision in the city for groundwater recharge as priority is given to concretisation rather than sustainable solutions. If the city continues to experience shortage in rainfall, it could lead to groundwater depletion, increase in local temperature and disappearance of vegetation,” said Prof TV Ramachandra of the Centre for Ecological Science at the Indian Institute of Science (IISc).
Citing one of his papers related to the Sharavathi river basin, Prof Ramachandra said the places that have seen large-scale deforestation have registered deficient rainfall as against places where the forest cover is intact. “The study shows enriching forest cover is the answer to beat deficient rainfall,” he said.