As a result of the large-scale conversion of forest land to crop land, particularly tea plantations in northeast India, there has been a 20 per cent reduction in green cover in the core monsoon zone.

Using satellite data and regional climate models, IIT Bombay researchers have found that deforestation (converting woody savannah to crop land) in northeast India and north-central India has led to a 100-200 mm reduction in summer monsoon rainfall in these two regions. The land use information is based on satellite data for two time periods — 1980-1990 and 2000-2010. The results were published on August 24 in the journal Scientific Reports.

During the initial phase of a monsoon, oceanic sources play a major role in bringing rain and charging the soil with moisture. But at the end of the monsoon period (August to September), evotranspiration from vegetation (also called as recycled precipitation) contributes to rainfall. Evotranspiration is a local moisture source for rainfall. Recycled precipitation contributes to 20-25 per cent of the total monsoon rainfall during the end of the monsoon and is very prominent in the Ganga Basin and northeast India. Read more