FLOOD INUNDATION MAPPING UNDER CLIMATE CHANGE USING LISFLOOD-FP MODEETHIOPIAL (A CASE STUDY OF KULFO WATERSHED),

Abstract

Floods account for about one-third of all geophysical hazards globally and adversely affect more people than any other natural hazards. This study focuses on flood inundation mapping under Climate Change on Kulfo watersheds. Projected future climate variables of one medium emission scenarios of RCP 4.5 were obtained from CORDEX-Africa program for Representative Concentration Pathway (RCP) for two future periods of (1971-2000) and (2041-2070). The climate data were bias corrected before serving as input to the analysis. Then, Mann-Kendall’s statistical tests were used for trend detection using XLSTAT 2016 were as HEC-HMS was used to estimate the peak flow. LISFLOOD -FP model was used for flood inundation mapping and flood depth extent. The study results indicate that minimum temperature, maximum temperature, and potential evapotranspiration significantly decrease in the future period of both baseline and near term of RCP 4.5, but the future projected precipitation shows increasing in both baseline and near term of RCP 4.5 scenarios. Due to this changes in climate parameters the peak flow is increased by 12 .9%, 8.6% and 8.3% in RCP 4.5 near term of RCA4, RACMO22T and HadGME2-ES models respectively. The projected flood depth will increase by the of 0.012 meter,0.16 meter and 0.047meter in RCP 4.5near term of RCA4, RACMO22T and HadGME2-ES models respectively. Due to thisthe flood depth, the flood extent will increase in the future period of RCP4.5near term as compare with baseline period in the catchment. Generally, the flood extent area and flood depth of Kulfo River watersheds are expected to increase in the future, as compared with baseline. Therefore, it needs reconstruct of gabion on that area to prevent the coming flood