Soil hydrologic group detection based on geomorphologic facieses and slope (Case study: Taleghan Watershed, Iran)

The main goal of this paper is to propose a new practical method for hydrologic soil group estimation in surface runoff process based on geomorphology facieses and slop. The determination of CN based on this method can reduce the time and cost of project. In this research the upstream rivers of Glinak Watershed have been used as a case study to examine the efficiency of proposed method with a comparison with CN method, the Rational and Creager methods. The results show that RSS of estimated flood based on - CN method with proposed and tradition CN and Rational to calibrated Creager's method are 31.5, 103.85 and- 11.39- , respectively. With these results, the new method can be proposed in various climatic conditions to estimate initial curve number in flood modeling and calibration. Keywords: Curve Number; Flood Discharge; Glinak hydrometric gauge