Impacts of land use/land cover on surface runoff in Kampala City and the surrounding Wakiso District

Abstract

Land use /land cover types in an area have an impact on surface runoff in that area during or after precipitation events. Large quantities of surface runoff can cause erosion, damage infrastructure and degrade ecosystems. There are limited studies on how the different land use/land cover types affect the total amount of surface runoff experienced. Therefore, the main objective of this study was to assess the impacts of land use/land cover on surface runoff in Kampala city and the surrounding Wakiso district. Qualitative data about the different land use/land cover types in the study area was obtained using Remote Sensing and Geographic Information Systems (GIS) techniques. The Soil and Water Assessment Tool (SWAT) model was used to simulate surface runoff. SWAT requires the land use/land cover data, soil data, climatic data, digital elevation model and many other features. It was found that the percentage of built-up areas in Kampala city is 71% while that of Wakiso is 20.7%. The percentage of bushlands and agriculture in Kampala city and Wakiso district were 14.5% and 31.6% respectively. The study also shows that, surface runoff increases as precipitation increases. Built-up areas experience much higher runoff than bushlands and agriculture. This study recommends further research to assess the impact of land use/land cover changes and climate variations on surface runoff. This study will help local council authorities to plan for infrastructure developments especially in the urban areas. The information from this study will also help the agencies in charge of the environment in Uganda for example Ministry of Water and Environment to design proper management strategies for surface runoff and water resources.