Application of Arc-GIS, HEC-GeoHMS and HEC-HMS in a holistic sense for estimation of rainfall-runoff process: case study over Ballikaya Basin

Abstract

In this paper, the relationship between rainfall and runoff is examined according to SCS-CN method based on DEM, soil and land use maps over Ballikaya Watershed. For the applicability of the method, firstly, the basin physical characteristics are compiled in Arc-GIS environment. Then, parameters related to the physical properties of the land are processed via HEC-GeoHMS, and continuous rainfall-runoff simulations are estimated by the HEC-HMS. The simulation parameters are conducted with five different objective function methods, and evaluations of the model performance are explained in addition to graphical methods with different metrics including NSCE, MRE and PCC. Results show that the HEC-HMS simulations capture time of the peak although predictions slightly underestimate value of the peak flows and runoff volume. Nevertheless, runoff fluctuation is simulated well respect to observed hydrographs over the watershed during both calibration and verification periods. In addition, the obtained simulation values with this study show that the hydrograph values of the rivers in the Ballikaya Watershed have the potential to be predicted via computer environment without any need from gauging measurements. Results can be used to investigate potential drought and flood risks over the region based only on the weather forecasts for the future studies.