Hydrological Soil Groups Estimation in Ungaged Catchment

In many floods controlling, watershed-management and water-resources projects, estimating of river flow-rate is important and needs a comprehensive hydrological modeling of flow-rate evaluation. Need for enlightening the status of water-resources and precipitation in different watersheds and the lack of networks of hydro-meteorological gauging stations, reveal the importance of estimating the runoff volume in watersheds. In addition, designing of hydro-structures on rivers such as bridges and weirs are in need of forecasting related floods of the territory. In this research explores discovering of the hydrological soil groups of Ab-Bakhsha watershed in Bardisr in Kerman province for evaluating the flood peak and volume. There is soil group data just for one sub-basin therefore; the watershed suffers from lack of hydrological soil group data. For that reason, slope maps evaluate the hydrological soil group which shows the 87% accordance with the available data. To continue, the HEC - HMS software modeled eight flood events using estimated data and rainfall-runoff observation. Four target-functions calibrated the model for curve number and coefficient K in Muskingum method. In the end, to evaluating the calibrated model, four flood events by NOF and EF goodness of fit tests were simulated. According to the results, the RMSE method as the best target-function used for optimizations. In general based on the lack of information about the soil curve number and promising results of this model, one can knows this method as a proper method for calculating the flood volume in preliminary study plans.