Impact of land use and cover change on rainwater sinks and flooding risk of Mbarara district

Abstract

As population increases, because of the need to grow more food or create settlements, Uganda has continued to change from one land use or land cover to another in various regions of the country. Specifically, the study was aimed at the extent of land use/cover change in Mbarara district and evaluate the impact of these changes on rainwater sinks and flooding risk for the district. A series of images from Landsat and Sentinel acquired for 2000, 2015 and 2022 were classified using a supervised classification procedure in ArcGIS to determine the land use/cover changes. Nasa Power tool was used to assess the potential of current rainwater sinks to handle runoff water within Mbarara. Results showed a variable and increasing trend in expansion of agricultural lands and built-up areas between 2000-2022. Agriculture expanded from 30,129.56 ha (24%) in 2000 to 32,440.95 ha (26%) in 2022. At the same time, built up increased from 2,941.84 ha (2%) in 2000 to 44,820.99 ha (36%) in 2022. Grasslands and wetlands were the most affected land cover types experiencing the highest level of changes in the study area.