International Journal of
Water Resources and Environmental Engineering

  • Abbreviation: Int. J. Water Res. Environ. Eng.
  • Language: English
  • ISSN: 2141-6613
  • DOI: 10.5897/IJWREE
  • Start Year: 2009
  • Published Articles: 344

Article in Press

Flood Hazard Analysis and Modeling of Big Akaki River Basin, Ethiopia

Alemayehu Hirko, Brook Abate

  •  Received: 19 September 2022
  •  Accepted: 04 November 2022
The study was carried out to analyze flood hazards and model the flood of Big Akaki River,Upper Awash River Basin, Ethiopia. The flood frequency distributions were conducted using Easy Fit 5.6 professional, thus, extreme value type one, was the best fitting probability distribution. The return period for the study area is 5, 25,50, 100 and 200 years were selected. The comparison of the observed and simulated hydrographs for the model performance Nash-Sutcliffe efficiency coefficient (NSE = 0.75), their correlation (R2 = 0.86) for calibration and (NSE = 0.74), their correlation coefficient (R2 = 0.89) for validation show that the model was appropriate for hydrological simulations. The flood inundated areas along Big Akaki River, that have been mapped based on the highest flows using the HEC-RAS model, GIS, and HEC-GeoRAS for interfacing between HEC-RAS and GIS, are 273, 308, 313, 322, and 332 hectares for5, 25, 50, 100 and 200 return periods respectively. The estimated cost of damage were 1643343, 1870526, 1913954, 1944978, and 2031831 USD were lost due to 5, 25, 50, 100 and 200 years return period respectively. The result of the study is very important as a preliminary information for land use planning, policy making, and investment decision as well as for security reasons to protect the area from the flood effect.

Keywords: Correlation Coeffficient, Easyfit, Flood Inundated Area, Hydrological Simulation, Nash-Sutcliffe efficiency coefficient and Validation