Rapid Urbanization over Gazipur District of Bangladesh: Impact Assessment on Forests and Local Climate Using Multispectral Remote Sensing Data

Abstract

Globally, the urbanization causes land use change and it results in decreasing the vegetation cover and increasing the Land Surface Temperature (LST). So the balance of environment is being destroyed. In this research, change of Land Use and Land Cover (LULC), Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) of the Gazipur District, Bangladesh from 2000 to 2021 were identified by analyzing Landsat 5 and Landsat 8 imageries with Google Earth Engine and ArcGIS tool. The results showed that deep forest area, water bodies and agricultural land were reduced from 14.48% to 10.13%, from 15.35% to 13.21% and from 25.54% to 21.1%, respectively. Light forest area and built-up area were increased from 40% to 47.18% and 4.58% to 8.4%, respectively, within the timeframe. Average NDVI was increased from 0.350 to 0.576. However, average minimum LST was increased by 1.044°C, average maximum LST was increased by 2.498°C and average mean LST was increased by 1.014°C from 2000 to 2021. The results showed a significant relationship between the growth of urban built-up and rising LST. Upazila with the most urban expansion, such as Sreepur and Kaliakair, exhibited the highest LST increases. A strong correlation was found between built-up area changes and maximum temperature (r = 0.98), and a moderate correlation with mean temperature (r = 0.72), highlighting the impact of urbanization on local temperature extremes. This research can help conserve the forest land, water bodies and agricultural land and facilitate the policy makers in sustainable and climate friendly city planning in Bangladesh.

The Chittagong Univ. J. Sci. 46(1): 206-229, 2025