* Extreme rainfall and flood risk show upward trend in most parts of India Even as the July 2005 deluge continues to haunt Mumbaikars,a recent report by the India Meteorological Department (IMD-Pune) reveals that the trend of one-day extreme rainfall is on the rise in states like Maharashtra. The study entitled impact of climate change on extreme rainfall events reports significant increasing trend in one-day extreme rainfall over the south peninsular region,Maharashtra,Gujarat region,Bihar and some other isolated areas. The study is co-authored by P Guhathakurta,O P Sreejith and P A Menon from IMD,Pune. Analysis of one-day extreme rainfall has shown that the intensity of extreme rainfall series has increased over coastal Andhra Pradesh and its adjoining areas,Saurashtra and Kutch,Orissa,West Bengal,parts of northeast India and east Rajasthan, it says. The findings have also been published in the latest issue of Journal of Earth System Science,Indian Academy of Sciences. The authors said the occurrence of exceptionally heavy rainfall events in recent years and the consecutive flash floods which caused heavy damage to economy and loss of life over three major metro cities,that is,Mumbai in July 2005,Chennai in October 2005 and again in December 2005 and Bangalore in October 2005,were the motivation behind the study. The maximum daily rainfall that a station can receive is on the rise in places like Mumbai and other coastal areas like Andhra Pradesh,parts of Gangetic West Bengal etc. However,places like Chhattisgarh,Jharkhand show a decreasing trend, said Guhathakurta. The report which looked at 2,599 rain gauge stations and 36 meteorological sub-divisions across India,says extreme rainfall and flood risk are increasing significantly in many sub-divisions of the country,except in some parts of central India. Increasing trends in the frequency of heavy rainfall days are observed over Konkan and Goa and adjoining regions of western coast and some isolated areas of eastern India. The frequency of rainy days events are increasing in peninsular,east and northeast India,while it is decreasing in major parts of central and north India, it says. The authors have concluded that increase in rain days have also been observed over most parts of Rajasthan. This indicates that the great desert areas of India are becoming wet. However,extreme southern parts of India like Kerala and Tamil Nadu are experiencing more dry days, says the report. Huge variations have been recorded in annual normal rainy days from 10 days to high frequency of 130 days across India. The study says that flood risk has also gone up alarmingly over India. Trend analysis shows that the increase of flood risk has increased significantly during the last two decades mostly over Konkan in Maharashtra,Gujarat,the eastern coast,West Bengal and UP, said Guhathakurta.
