Flash flood inundation assessment for an arid catchment, case study at Wadi Al Jizzi, Oman

Abstract

Lack of high-resolution data and inappropriate integration of different data sources make modelling flash flood even more complicated. The IHACRES and AHP models were used to estimate floods for the period 1987 to 2007 for Wadi Al Jizzi arid catchment. The IHACRES model results showed that the average simulated flood was 0.36 m3/s, while that observed for all flood storms was 0.30 m3/s. The average readjusted AHP Simulated Flood for three statically defined clusters: low, moderate, and high rainfall was 3.55, 3.20, and 3.75 m3/s, respectively. The average observed flooding for low, moderate, and high rainfall were 3.23, 1.54, 3.07 m3/s. Pearson correlation between observed and simulated flood showed significant values for IHACRES and AHP with a range of 0.84 and 0.89 respectively. The Nash-Sutcliffe efficiency of the IHACRES model was 0.78, while it shows a good performance for low and high AHP re-adjusted values, which was 0.81 and 0.82.