Prediction of Surface Water Resources in Danjiangkou Basin Based on ESP and Distributed Hydrological Model

 The prediction of surface water resources in the Danjiangkou Basin is of great significance for the design of the water transfer plans for the South-to-North Water Diversion Project. However, it is difficult to obtain high-precision simulations for mid- and long-term hydrological forecasting. Based on the thought of extended streamflow prediction (ESP) and distributed hydrological models, this paper proposed a set of forecasting systems for predicting the annual surface water resources in the Danjiangkou Basin. Firstly,  the Wetspa model  was established to forecast the inflow of Danjiangkou reservoir. The Nash efficiency coefficients of the monthly average runoff during the calibration period (2006-2012) and verification period (2013-2016) were 0.97 and 0.95, respectively. Secondly, it was assumed that the rainfall of 2017 could be predicted by the rainfall forecasting model, then the rainfall process was obtained based on the ESP and the runoff process of the basin outlet was calculated through the Wetspa model. Finally, the predicted surface water resources of the Danjiangkou Basin in 2017 was 45.448 billion m³, and the actual surface water resources is 40.395 billion m³, with a relative error of 12.51%. The results showed that the prediction of surface water resources in Danjiangkou Basin based on ESP and distributed hydrological model could provide a certain reference for the design of water transfer plans of the Danjiangkou Reservoir.

Key words: Water resources prediction; ESP; Wetspa model; Nash coefficient