Title: Efficacy of slope-adjusted curve number models with varying initial abstraction coefficient for runoff estimation

Authors: Sangeeta Verma; Anju Singh; Surendra Kumar Mishra; Pushpendra Kumar Singh; Ravindra Kumar Verma

Addresses: Environmental Engineering and Management Group, National Institute of Industrial Engineering (NITIE), Vihar Lake, Mumbai, Maharashtra, India ' Environmental Engineering and Management Group, National Institute of Industrial Engineering (NITIE), Vihar Lake, Mumbai, Maharashtra, India ' Water Resource Development and Management, Indian Institute of Technology, Roorkee, Uttarakhand, India ' Water Resources Systems Division, National Institute of Hydrology (NIH), Roorkee, Uttarakhand, India ' National Mission Himalayan Studies (NMHS), G. B. Pant National Institute of Himalayan Environment and Sustainable Development (GBPNIHESD), Kosi-Katarmal, Almora, India

Abstract: The present study evaluated the efficacy of three slope adjusted CN2 models as well as original SCS-CN method using LISS-III and ASTER DEM data. The performance of these models was also evaluated for four different values of initial abstraction coefficient (λ), i.e., 0.05, 0.1, 0.2 and 0.3 for the Kalu watershed in Maharashtra, India using R² and RMSE. The results show that slope adjusted CN formulation given by the Sharpley and Williams (1990) (Model 2) for λ = 0.3 performed the best with lowest RMSE (10.88) and highest R² (0.8757) in comparison to the other models. On the contrary, original SCS-CN model performed the worst. Results also show that watershed slope is an important factor affecting runoff generation and hence due consideration should be given to it in planning of soil and water conservation structures. This study also revealed that RS and GIS techniques are useful for estimating as SCS-CN model input data to predict runoff more accurately.

Keywords: SCS-CN method; runoff; slope adjustment; initial abstraction coefficient; RS and GIS.

DOI: 10.1504/IJHST.2018.095534

International Journal of Hydrology Science and Technology, 2018 Vol.8 No.4, pp.317 - 338

Received: 20 Feb 2017
Accepted: 11 Apr 2017
Published online: 09 Oct 2018 *

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