Seasonal rainfall deficiency sparks concern

Change in orientation of monsoon circulation could be the reason

Even as the southwest monsoon continued to advance into the northern parts of the country, Kerala has registered a seasonal rainfall deficiency of more than 20%, with Wayanad recording the highest deficit of 61% up to July 9.

Even though the southwest monsoon has almost three months left to complete its run, the seasonal deficiency has left observers and planners worried about the impact on agriculture and water supply. A forecast issued by the India Meteorology Department for the next two weeks indicates a weaker phase of the monsoon over Kerala, marked by fairly widespread or scattered rain.

The skewed rainfall distribution in the State could be taken up for a detailed study by the Regional Climate Centre, Pune, to assess the causative factors and develop mitigation strategies. M. Rajeevan, Secretary, Ministry of Earth Sciences, told

The Hindu that the study was significant in the light of the latest finding that Kerala as a whole was receiving less rainfall during the southwest monsoon season.

Citing a recent research work by the IMD, he said the change in the orientation of the monsoon circulation could be behind the rainfall deficiency in the State. “The downward trend could have far-reaching implications for the State that depends on the monsoon for agriculture and water storage in reservoirs”.

Kerala receives a major portion of its annual rainfall (more than 2,000 mm) during the southwest monsoon period from June 1 to September 30. Last year, the State registered a 34% deficit during the season, followed by a crippling shortfall of 62% during the northeast monsoon from October to December, leading to drought conditions in most districts.

Wayanad, the hub of coffee and spices cultivation in Kerala, recorded a 59% rainfall deficit during the southwest monsoon last year, which went up to 68% during the northeast monsoon season. “If the 61% deficit up to July 9 is an indication, the situation is likely to be no different this year,” says an official with the Agriculture Department.

Idukki looks grim

The rainfall deficit in Idukki, another key district where most of the State’s hydel power is generated, is another cause for concern. The seasonal deficit is already touching 34%. Last year, the district registered a deficit of 31% from June to September and 69% during the northeast monsoon period.

The total water storage in the 16 hydroelectric reservoirs in Kerala stood at 21% of the capacity on Saturday, enough to generate just 870.63 million units of electricity. This is 432 million units less than the storage capacity last year.