Simplified sediment yield index model incorporating parameter curve number

Runoff sediment process modeling is highly variable and nonlinear in nature. In the present study, an attempt has been made to develop a relationship between Soil Conservation Service Curve Number (SCS-CN) and Sedimen Yield Index (SYI) for the Narmada watersheds (Madhya Pradesh). Only area (A), delivery ratio (DR), and curve number (CN) were used as input for model development. High value of Nash-Sutcliffe efficiency of (eta) 98.60 and 88.19 % for Shakkar watershed and for combined watersheds, respectively, shows that the proposed simplified SYI model is found to be suitable for the study area. The resulting higher (0.98 for Shakkar and 0.88 for combined watersheds) coefficient of determination (R (2)) values strongly support the versatility of the derived relationship and invokes assessment of SYI from the available National Engineering Handbook (NEH-4) CN values. Thus, the prediction of SYI is important in order to adopt the suitable soil conservation measure in the study watershed for minimizing the soil erosion.