Hydrological Modelling of Bina River Basin in Madhya Pradesh, India

Rainfall-runoff models have been widely used through the last century all over the world. These models help to build a trustworthy relationship between the precipitation and runoff. The relationship between rainfall and runoff is essential in a catchment for hydrologic analysis and design. In the current paper, our main objective is to compute runoff by employing two hydrological models namely SCS CN and RRL toolkit Australian Water Balance Model (AWBM) and to check the which model is more suitable for runoff estimation in the Bina basin. The SCS CN method is an empirical approach for estimation of Direct Runoff. The SCS CN method is highly trusted method and used by the hydrologists all over the globe for prediction of runoff. With SCS CN model, Arc Map 10.2 GIS tool is used to generate the soil map, the land use map and ultimately the composite curve number of the watershed is calculated. In the second model, RRL toolkit software is used in which the AWBM is selected for assessing the runoff. The AWBM is a catchment water balance model that relates runoff to rainfall with daily or hourly data. The daily rainfall data, and daily evapotranspiration data was given as input for the AWBM RRL toolkit. In total 5 years of daily data (1990-94), first 3 years of data was taken for model calibration and the rest 2 years data was taken for model validation. The coefficient of determination for the models was obtained indicating good agreement between the observed and simulated runoff. The models were also evaluated based on Nash–Sutcliffe Efficiency Index (EI). The Nash Sutcliffe efficiency obtained for calibration and validation of AWBM was found to be 0.852 and 0.890 respectively.

Keywords: SCS CN; RRL; AWBM; Evapotranspiration; Nash-Sutcliffe efficiency