The Kolkata megalopolis began with a population of 100,000 in 1735 and has grown to the present 7 million, reflecting largely uncontrolled growth over the past 300 years. There is past empirical evidence to show that all over the world, increasing population in cities and adjoining suburbs has restricted the planned development of any burgeoning city. This is more prominent in the developing countries, where unplanned urban sprawl along with its unprecedented effects changes the overall environment, climatic pattern, and ethical character of the city.

This paper will assess the extent of urban growth of Kolkata over the years, characterize its future growth pattern, and determine its influence on pre-monsoonal precipitation. The first objective is to conduct an analysis using historical maps and satellite images to delineate the extent of urban growth, highlighting the factors which led to this population explosion. We will investigate whether trends in pre-monsoonal rainfall over the last 100 years are correlated with urban growth. The second objective is to determine the growth of Kolkata in the next 25 years, using the urban growth model, SLEUTH. The third and final objective is to see if there is any anomaly in the rainfall pattern, in and around Kolkata, under pre-, current, and 2025 urban land cover scenarios using the WRF-NOAH mesoscale model.