Impacts of land use and land cover change on surface temperature in the north-western region of Bangladesh

摘要

Land use and land cover change can significantly contribute to overall climate change. Again, vegetation coverage of any region can highly influence the land surface temperature distribution. Being one of the largest deltas in the world, Bangladesh is highly vulnerable to natural disasters because of its geographical location. The physiography of the north-western region of Bangladesh affects the spatio-temporal distribution of weather parameters e.g. temperature, precipitation, humidity etc. Every year people of this region suffer from extreme events like drought, severe heat wave, erratic rainfall etc. Due to inadequate weather data, it is often difficult to analyze various natural as well as human induced climatic events. In this study, the impact of land use and land cover change has been assessed with respect to the spatio-temporal variation of several satellite derived indicators including land surface temperature within the study area. Landsat 5 TM data of the years 2003, 2008, 2010 and 2011 have been analyzed for the aforementioned purposes. Each image has gone through various steps of pre-processing e.g. band compositing, radiometric corrections etc. Satellite derived parameters of greenness (NDVI), moisture (NDWI), imperviousness (NDBI) and land surface temperature (LST) were used as the indicators of environmental monitoring. It has been found that the temperature is comparatively low in vegetation area but high in non-vegetation area. Again, compared to non-built-up areas, the temperature is higher in the built-up areas. In this study, it is observed that the temperature has been increased by 6°C from 2003 to 2011, whereas, water area has decreased by 270.28 km^{2of this region. Finally, relationships between LST, NDVI, NDWI and NDBI have been established. It is found that the relation between LST and NDBI is positive while LST-NDVI and LST-NDWI are negatively correlated.}