Abstrakt: |
Analysis of flood frequencies is critical for water resources applications. However, the majority of rivers in developing countries like Ethiopia are either poorly gauged or completely ungauged, resulting in limited data for flood frequency analysis in those nations. In such cases, stream flow (SF) modeling is the only option to acquire the SF data for various water resources applications. In this study, the possibility of using the PyTOPKAPI hydrological model together with the flood frequency methodologies for flood frequency analysis was examined. The aim is to extend the PyTOPKAPI model application to flood frequency analysis in data-limited (ungauged) catchments. Consequently, this study was conducted on Aweitu Ethiopian catchment defined by its two flow outlets (Aweitu Nr Babu, 268 Km2and Aweitu at Jimma, 96 Km2) in Jimma town. The investigation of flood frequencies based on the PyTOPKAPI model-simulated stream flow data was carried out. The results of the analysis were then compared with those of the corresponding observed stream flow data of 29 years for Aweitu Nr Babu and 25 years for Aweitu at Jimma. The overall output of the comparisons revealed that simulation-based flood frequency analysis produced slightly greater flood quantiles than the corresponding observed stream flows especially for higher return period. This approach seems new to flood frequency analysis in this context. In summary, the study results suggest that the PyTOPKAPI model-simulated stream flow can be used for flood frequency analysis and other water resources applications in data-limited regions. This work, in addition to reflecting recent advances, focuses on the use of simulated stream flow information for flood frequency analysis, which has received less attention in Ethiopia. The novelty of this work provides the framework for improving flood frequency analysis in developing countries for water resources planning and flood risk management. |