Jafar Chabokpour - Associate Professor, Department of Civil Engineering, University of Maragheh, Maragheh, Iran.

In this paper, the evaluation of the performance of five flood prediction models in the Simineh-Rood River, Lake Urmia basin, Iran, is discussed in detail. To this purpose, the performance of Transfer Function, Saint-Venant equations, Artificial Neural Network, Adaptive Neuro-Fuzzy Inference System, and Support Vector Machine models are evaluated for ۲۰۱۸ and ۲۰۱۹ flood data. Specifically, the models are rated according to their accuracy, computational efficiency, and robustness under different flow regimes and at various forecast times. This now leads to a maximum Nash-Sutcliffe Efficiency of ۰.۹۱ for the Saint-Venant equations during the ۲۰۱۹ flood event, followed by ANN with ۰.۸۹, ANFIS with ۰.۸۷, SVM with ۰.۸۵, and lastly, Transfer Function with ۰.۷۸. The same is the case for peak flow discharge, which was best predicted by the Saint-Venant model to be ۱۹۳.۸۰ m³/s while the observed value was ۲۰۰.۸۳ m³/s. This model maintained its consistency with respect to low, medium, and high flows, where the values of NSE were ۰.۸۹, ۰.۹۲, and ۰.۹۱, respectively. However, compared to the other models, which took ۰.۵–۸ s, it had a much larger computational time, ۱۲۰ s for a ۷۲-h simulation. The sensitivity analysis returned variable model responses to the quality of the input data; an input variation of ۲۰% reduced the NSE of the Saint-Venant model to ۰.۷۳ and that of the Transfer Function to ۰.۴۴. This study provides quantitative insight into the choice of flood prediction methods in a semi-arid region, with respect to required accuracy, computational resources, and forecast lead-time.

Flood prediction, Lake Urmia, Soft computing methods, Transfer function