Mapping Flood Zone in Khorram Abad River by Integrating Hydrological and Hydraulic Models

The aim of this study is to investigate the application of an integrated hydrological-hydraulic modeling approach to simulate river flows, flood hydrographs, and flood-prone areas in the Khorram Abad (Iran) drainage basin. In this study, the WetSpa hydrological model and the LISFLOOD-FP hydraulic model were used to simulate river flows and flood zones. Ten years of meteorological data (water years ۲۰۰۵–۲۰۰۶ to ۲۰۱۴–۲۰۱۵) were employed for the simulations. The models were calibrated using data from the first five years, while the subsequent five years of data were used for validation. The WetSpa model was applied to simulate daily flows, and the LISFLOOD-FP model was used to simulate flood-prone areas for different return periods. The WetSpa model successfully simulated daily flows with acceptable accuracy, achieving performance metrics such as the Nash-Sutcliffe Efficiency (NSE) of ۰.۵۳ and the Kling-Gupta Efficiency (KGE) of ۰.۶۸. For high-flow events, the NSE coefficient reached ۰.۷, indicating the model's effectiveness in flood prediction. The results from the LISFLOOD-FP model showed that the maximum flood extent for the ۲۰۰-year return period was ۶۲۷,۱۰۰ square meters. The water balance analysis revealed that ۲۵.۵% of the precipitation was converted into runoff, comprising ۲.۳۴% surface runoff, ۱.۶% subsurface runoff, and ۲۱.۵۷% groundwater flow. This study demonstrates that the integration of hydrological and hydraulic models can effectively predict flood behavior and delineate high-risk areas.

کلیدواژه ها:

Floods ، WetSpa Model ، LISFLOOD-FP model ، River flow simulation ، Khorram Abad