Simulating Land Cover Changes and It’s Impacts on Land Surface Temperature: A Case Study in Rajshahi, Bangladesh
Description
Land Surface Temperature (LST) has been used to investigate the effects of changing land cover on climate. The importance of surface temperature in a range of earth science concerns and themes, such as urban climatology, human-environment interactions, and global environmental change, cannot be overstated. Its impact will be more in the monsoon areas, because the rainfall is unpredictable, failure of monsoon and there will be heavy down pour of rainfall. LST for Rajshahi division, Bangladesh, is derived using ArcGIS software from images of Landsat 8 Optical Land Imager (OLI) data of 30 m resolution and Thermal Infrared Sensor (TIR) data of 100 m resolution, as well as data from Landsat-5 Thematic MAPPER (TM) satellites. A total time span of 15 years, starting from 2005 to 2020 is selected. Land cover map, Land Surface temperature, Normalized Difference vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) are calculated at every 5 years interval starting from 2005. The digital number of thermal infrared band is converted into spectral radiance using the equation supplied by the Landsat user's guidebook. The effective at sensor brightness temperature is obtained from the spectral radiance using Plank's inverse function. The final LST is computed using surface emissivity based on NDVI classes. according to the study, LST is increasing with the passage of time. The northwest parts of the Rajshahi division have the highest LST values. LST and NDVI are found to have a considerable positive correlation. The study shows the increase in vegetation reduces LST and the decrease of vegetation is responsible for increased LST. Also, bare soil, built-up area, waterbody is responsible for controlling LST. From the land cover map, it is visible that, bare soil and water body has a slight effect on LST but on the other hand, LST increases with growing of built-up area. The spatial distribution statistics of Land cover map, LST, and NDVI can be used as a guideline for urban planning, methods for improving the quality of the urban environment and a possible solution for diminishing of LST.