Determining the Urban Heat Island intensity of Kolkata City with suggestive mitigation techniques

Kolkata City in eastern India is one of the four largest megalopolises of India with a population of over 15 million (Census of India 2011). To contain this huge populace the city is going through brutal landuse landcover change (LULCC) in the recent decades. The eastern part of the city is seeing the maximum transformation of pervious surface to impervious surface where the wetlands are being built on continuously. This transformation is bound to have some impact on the microclimate especially temperature around the city. It is important to quantify the urban heat island intensity across the length and breadth of Kolkata to see how temperature patterns are modifying due to LULCC. Thus a one month pilot study was conducted to quantify the urban heat island (UHI) intensity of Kolkata City covering sections of June and July 2013. This is a part of an ongoing two years project undertaken by Auburn University, Department of Geology and Geography and the Indian Meteorology Department of Kolkata. To measure the UHI intensity data logging sensors has been installed in 30 different stations in and around the city. These sensors have captured temperature readings at an interval of 60 minutes. The comparisons of temperature between city core areas and surrounding rural areas have shown that Kolkata city core is hotter than its suburban rural/semi-rural areas. Some of the locations within the city are urban parks and urban water bodies which bring out the significance of having more urban parks and ponds to reduce the UHI impact. This study is in the backdrop of heat waves which are becoming common every year. 2009, 2010 and 2012 have recorded incidents of heat wave in Kolkata. How will the city people cope with such heat and consequent power and water crisis? Thus it is important that sustainable methods are implemented in Kolkata and other Indian cities to ameliorate the impacts of climate change and their individual UHI effects.