Author(s): Seith N. Mugume; Kato Ronnie; Edgar Atuhairwe; Emmanuel Tumwesigye

Linked Author(s): Seith Mugume

Keywords: Climate change; Fluvial flooding; Global climate models; Land use change; Statistical downscaling

Abstract: Globally, flooding affected an estimated 109 million people leading to loss of lives and destruction of property and livelihoods. Over 62% of these consequences were attributed to fluvial flooding which has been exacerbated by global climate change, rapid urbanization, and land use change in recent years. The recent flooding events in the transboundary River Semliki, resulted in displacement of more than 17,000 people in 2019. However, there are very limited studies that have assessed the singular effects of climate and land use changes on flood risk in the catchment. This study focused on assessment of the singular impacts of climate and land use changes on flood risk in the lower reaches of River Semliki in Ntoroko district, Uganda. Four Global Climate Models (GCMs) were statistically downscaled for two future climate scenarios (SSP2-4.5 and SSP5- 8.5) to determine climate change impacts of daily rainfall and temperature and hence flooding. GIS-based spatial analysis techniques were applied to assess current and future 2050 and 2080 land use change effects. Subsequently, a hydrological model was developed, calibrated, and applied to simulate river flow peak discharges for flood mapping. The study results suggest that the projected 2080 land use change will lead to a smaller increase in flooding extent of 5.28% [3.26 - 7.31% ]. On the other hand, the projected 2080 future climate change scenarios resulted into higher increase in flooding extent of 33.9% [10.5 - 78% ]. The study findings could support identification and prioritization of suitable flood mitigation and adaptation strategies for the Semliki Catchment.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0647-cd

Year: 2023