Identification of urban hotspot areas from remote sensing towards implementing heat mitigation strategies: a case study over Navi Mumbai, India
摘要
Urbanization alters the character of the surface resulting in increased temperatures over cities compared to rural areas. This Urban Heat Island (UHI) phenomenon has several disadvantages such as health impacts, increased demand for cooling etc. Urban planners need to be informed clearly about locations within the city that needs immediate attention in terms of heat mitigation measures. Though Surface UHI (SUHI) maps derived from satellite observed Land Surface Temperature (LST) data are available, they cannot be used directly to prioritize thermal hot spots within the city. This study over Navi Mumbai, India demonstrates how combining SUHI, vegetation and population information helps to identify hotspots. Long-term trend analysis of Landsat satellite derived SUHI intensity, NDVI and population data indicated places with severe heat ingress. The results indicate a progressive warming trend in the northern region of the city over time, while the western and southern boundaries maintain relatively cooler temperatures. Despite undergoing urbanization with high-rise structures, the southern parts of the city experienced cooling trends attributed possibly to the presence of mangrove vegetation and coastal expanses. Dense residential and industrial areas located inland primarily exhibited increasing temperature conditions demanding urgent heat mitigation actions.