Assessing land use and land cover changes in three selected grama niladhari divisions in homagama parallel to the evolution of techno-city project

Abstract

Homagama Techno-City project is one of the largest projects in Sri Lanka with over 182 ha of area focusing on promoting artificial intelligence, distributed computing, robotics, genetics, nanotechnology, and bioengineering and it is essential to determine the environmental impact caused by the land use change for the sustainable development of the area further. Therefore, this study was conducted to (I) analyze the land use /land cover changes in three GN divisions (Pitipana South, Pitipana North, Dampe), of Homagama Sri Lanka over the years 1980 to 2022 by using Geographic Information System (GIS) maps and geometric calculations and (II) to estimate the environmental impact of land use changes by analyzing runoff coefficients of the area from 2003 to 2022. Three GIS maps were generated for three GN divisions using Arc GIS (version 10.8) for the years1980, 2003, 2022 separately and geometry calculations were carried out. For the determination of the environmental impact, runoff coefficients were calculated. The mainland uses of Pitipana GNs were classified as paddy, cultivation, forest, residential, Techno-City, rocks & bare lands, and unknown lands. The Techno-City project accounts for 4.4% of the total land area. The total cultivation area has been decreased by 11% while the residential area has been increased by the same percentage from 2003 to 2022. According to the developed GIS map for the land use in the year 2003, paddy land area represents 14.5% of the total area, while cultivations, forest, residential areas, rocks and bare lands account for 18.99%, 24.35%, 35.15%, and 7% respectively while it was 14.21%, 7.97%, 19.42%, 46.41%, 7,14%, and 4.38% for paddy cultivations, forest, residential, rocks, bare lands, and Techno-City respectively in the year of 2022. There is no significant difference in runoff coefficient in the year 2003 (0.32) and 2022 (0.30) with the land use change according to the study. A detailed study is recommended and will be beneficial for preserving the sustainability of the area.