Complementary system-theoretic modelling approach for enhancing hydrological forecasting

摘要

Hydrologic models generally represent the most dominant processes since they are mere simplifications of physical reality and thus are subject to many significant uncertainties. As such, a coupling strategy is proposed. To this end, the coupling of the artificial neural network (ANN) with the Xin'anjiang conceptual model with a view to enhance the quality of its flow forecast is presented. The approach uses the latest observations and residuals in runoff/discharge forecasts from the Xin'anjiang model. The two complementary models (Xin'anjiang &ANN) are used in such a way that residuals of the Xin'anjiang model are forecasted by a neural network model so that flow forecasts can be improved as new observations come in. For the complementary neural network, the input data were presented in a patterned format to conform to the calibration regime of the Xin'anjiang conceptual model, using differing valiants of the neural network scheme. The results show that there is a substantial improvement in the accuracy of the forecasts when the complementary model was operated on top of the Xin'anjiang conceptual model as compared with the results of the Xin'anjiang model alone.