Analyzing the effects of land use and land cover changes on paddy cultivation using Remote Sensing: A case study of Sooriyawewa, Sri Lanka

Abstract

Land-use and land-cover (LULC) change research is a type of environmental research that is intimately linked to socioeconomic development. At present, the LULC changes are mainly occurred due to physical developments and agricultural purposes. Paddy is the major crop and mostly grown in Sri Lanka. Hambantota district rank as fifth place in rice production in Sri Lanka. Sooriyawewa is the driest and mostly grown paddy Divisional Secretary Division (DSD) in Hambantota District, but nowadays there are so many reasons that hinder paddy cultivation. This research aims to identify the existing system for monitoring the LULC changes in paddy cultivation and applicable Remote Sensing techniques, then quantify the LULC changes over paddy cultivation in Sooriyawewa during the past four decades and finally examine the underlying causes for LULC changes over the paddy. For this research, downloaded Landsat images from 1980 to 2019 with a specified time gap and Supervised classification was used for the land cover classification for all images to detect the paddy variation in this area. Obtained net changes between 1980-2019 are Paddy, Other crops, Forests, Waterbodies, Built up areas and barren lands. According to the LULC changes between 1980-2019, there was a -15.50% decrease in paddy areas but built-up areas, other crops significantly increase 11.97%, 10.08% respectively. This is a temporal problem in this area and this study is essential for the relevant authorities for decision making, preparing urban development plans, where planned infrastructural development and supervision, land use planning, natural resource conservation and environmental sustainability.