Spatial variation of temperature and indicative of the urban heat island in Chennai Metropolitan Area, India

Heat island is the main product of urban climate, and one of the important problems of twenty-first century. Cities in tropical countries suffer extensively due to the urban heat island effect, and urban climate studies are necessary to improve the comfort level and city planning. Chennai is the tropical city; it is the fourth largest metropolis in India and one of the fastest growing economic and industrial growth centers in South Asia. The spatial distribution of heat intensity in Chennai Metropolitan Area was studied, and the influence of land use and green cover were analyzed in the present work. Mobile measurements were carried out throughout the study area using a grid network to represent various land use patterns of the city. The study revealed some heat and cool pockets within the city limit; the maximum intensities of temperature were noticed in the central core city and north Chennai, which are distinguished for their commercial centers and densely populated residential areas. In morning time, temperature differences between fringes and central parts of heat packets were in the range of 3-4.5 degrees C. Land use and green cover play a critical role in microclimate and influences it. Green cover has a significant negative correlation with observed microclimate variations. Thus, the study urges city administration, policy makers, and architects to take up effective mitigation and adaptation strategies in the city to make people more comfortable.