URBAN HEAT ISLAND CHARACTERIZATION USING THERMAL REMOTE SENSING DATA

Abstract

The rate of urbanization for India (1.1%) being higher than the world’s average (0.9%) makes it absolutely important for the policy makers to monitor the growth of the cities and take well informed socio-economic decisions. In this study, we perform temporal assessment of remote sensing data, to see the growth of the city in terms of UHI. We emphasize on the assessment of land surface temperature (LST) derived from MODIS data over a period of 19 years from 2000 to 2018. The temporal analysis of the urban heat island effect of the mature cities can be one of the important factors to plan the growth of the maturing cities. It is well understood that urbanization leads to growth of not only the economy and the infrastructure of the city, but also to lateral expansion of the city limits towards the surrounding rural areas. Various factors play a role in the expansion of the city and the form of the urban sprawl it’s indicative of. In this study, thermal remote sensing data is used to analyze the urban heat island effect of the major cities of the country, recording geometric parameters that determine the magnitude of individual UHIs, the spatial extent of UHIs and the orientation of the UHIs. Thermal remote sensing has been used over urban areas through an image analysis procedure to assess the urban heat island (SUHI). Urban-rural temperature differences were determined by modelling the SUHI as a two dimensional Gaussian surface superimposed on a planar rural background. The application of this fitting technique allows us to parametrize the SUHI pattern in order to better understand its intensity trend and also to perform quantitative comparisons among different images in time and space. This methodology will help the policy makers understand the urban heat island signature of the cities and take well informed decisions to plan the growth of the city.