Flood hazard mapping and analysis under climate change using hydro-dynamic model and RCPs emission scenario in Woybo River catchment of Ethiopia
ISSN: 1708-5284
Article publication date: 3 January 2022
Issue publication date: 5 May 2023
Abstract
Purpose
The purpose of this paper is to prepare flood hazard map and show the extent of flood hazard under climate change scenarios in Woybo River catchment. The hydraulic model, Hydrologic Engineering Center - River Analysis System (HEC-RAS) was used to simulate the floods under future climate scenarios. The impact of climate changes on severity of flooding was evaluated for the mid-term (2041–2070) and long-term (2071–2100) with relative to a baseline period (1971–2000).
Design/methodology/approach
Future climate scenarios were constructed from the bias corrected outputs of five regional climate models and the inflow hydrographs for 10, 25, 50 and 100 years design floods were derived from the flow which generated from HEC-hydrological modeling system; that was an input for the HEC-RAS model to generate the flood hazard maps in the catchment.
Findings
The results of this research show that 25.68% of the study area can be classified as very high hazard class while 28.56% of the area is under high hazard. It was also found that 20.20% is under moderate hazard and about 25.56% is under low hazard class in future under high emission scenario. The projected area to be flooded in far future relative to the baseline period is 66.3 ha of land which accounts for 62.82% from the total area. This study suggested that agricultural/crop land located at the right side of the Woybo River near the flood plain would be affected more with the 25, 50 and 100 years design floods.
Originality/value
Multiple climate models were assessed properly and the ensemble mean was used to prepare flood hazard map using HEC-RAS modeling.
Keywords
Acknowledgements
The authors would like to thank all data providers, namely, MWIEE (Ministry of Water Irrigation and Energy of Ethiopia), for providing the river flow data, NMAE (National Meteorology Agency of Ethiopia) for providing the climate data. The authors are thankful to Arba Minch University who has provided all logistic support in conducting the research work.
Citation
Ukumo, T.Y., Abebe, A., Lohani, T.K. and Edamo, M.L. (2023), "Flood hazard mapping and analysis under climate change using hydro-dynamic model and RCPs emission scenario in Woybo River catchment of Ethiopia", World Journal of Engineering, Vol. 20 No. 3, pp. 559-576. https://doi.org/10.1108/WJE-07-2021-0410
Publisher
:Emerald Publishing Limited
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