Abazar Esmaili; Mohammad Golshan
Abstract
Watersheds are a vast area with different conditions that simulation and studying the processes of runoff and sediment production in these area are critical for managing and maintaining resources. The Kozatopraghi watershed with an area of 766 km2 is located in the south and upstream of the Garesou basin, ...
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Watersheds are a vast area with different conditions that simulation and studying the processes of runoff and sediment production in these area are critical for managing and maintaining resources. The Kozatopraghi watershed with an area of 766 km2 is located in the south and upstream of the Garesou basin, Ardebil province. Between the hydrological models, based on the capabilities of the SWAT model, this model was used to simulate the hydrological processes of the area in sub watershed scale. Also, for a more accurate examination the rainfall simulator was used in the hydrologic response units (HRUs), the obtained results were generalized to the sub watershed scale. The results of SWAT model were assessment with statistical parameters R2, NSE and RMSE. In the calibration and validation periods these coefficients for simulation runoff obtained 0.8-0.74, 0.71-0.69 and 0.32-0.33, respectively, and for simulation sediment yield obtained 0.75-0.66, 0.72-0.64 and 35.27-26.39, respectively. Assessment the obtained results of rainfall simulator showed that Loamy soils, located in 8 HRUs have high effect in sediment yield production. The maximum runoff and sediment yield by rainfall simulator and SWAT model were observed in sub watersheds 13 and 1, that indicating poor and inappropriate conditions in these subwatersheds. Comparing the study methods showed that the SWAT model have better performance than rainfall simulator for simulation runoff. Also, the estimated sediment yield by this model is lower than rainfall simulator that is close to observed values.
Mohammad Golshan; Abazar Esmaili; ali afzali; Afshin Jahanshahi
Abstract
Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed ...
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Simulation with using of computer models are developing very fast and these models are essential tools for understanding of man from the watershed and hydrological processes. In this study IHACRES and HEC-HMS rainfall runoff models was used for simulation of four flood hydrographs in Kasilian watershed with area 67.8 square kilometers in Mazandaran province. To prepare the Requirements maps for running HEC-HMS model was used HEC-GeoHMS extension. Hyetograph data with 15 minutes time step and its related hydrograph was entered to two models based on 1 hour time step. Then simulation of the flood hydrograph was done based on 15 minutes time step. CP and RE% statistical coefficients was used for evaluation of models performance. Values of this coefficients using the HEC-HMS model for flood 26 November 1994 was calculated 0.72 and 118.26 respectively and for flood 6 October 1996, 0.89 and -24.63 respectively and using the implementation of IHACRES model these coefficients in the first flood was calculated 0.63 and 152.4 respectively and in the second flood 0.79 and -35.6 respectively. The results showed that both use models have acceptable performance for simulation of flood hydrograph in this area and HEC-HMS model has better performance in compared with IHACRES model.
