Remote sensing and GIS approach to assess landform changes in Kaduwela divisional secretariat area and its impacts to the environment

Abstract

Land use/land cover (LULC) change plays one of the major key roles in environmental impacts, and it is common to all nations. Monitoring this LULC change together with quantifications of environmental changes is an important concept in the Sustainable Development process. Therefore, remote sensing and geographic information system technique (RS & GIS) was used to exploit the variation of the LULC pattern, and satellite images of five years between 1997 and 2019 were used in this research. LULC changes in the Kaduwela Divisional Secretariat area were analysed using the Maximum likelihood supervised classification method and found that there was a significant decrease in vegetation cover due to rapid urbanisation. To assess landform changes and their impacts on the environment, normalised difference vegetation index (NDVI), normalised difference built-up index (NDBI), and land surface temperature (LST) were used. Further, relationships inbetween them were used to analyse the correlations between NDVI and LST, NDBI and LST, and NDVI and NDBI, and it was noticed that negative, positive, and negative correlations respectively among them. It indicates that healthy vegetation can decrease the land surface temperature, whereas built-up will enhance land surface temperature. More than 70% of overall accuracy for LULC classification was able to achieve in this study.