Combined Flood Forecasting Model Of Hydrology And Hydraulics

Having been developed for decades of years, hydrologic model and hydraulic model for channel water converging became more and more sophisticated. We already had good results when we used them practically. But we also found that single hydrologic model or hydraulic model couldn't cope with some complex channel water converging problems. Therefore we should synthesize the two models mentioned above when in practical use.Comparatively, the river channel that I've studied in this thesis is gently. In this case , it's reasonable for us to use the hydraulic method to carry out flood forecasting. But on the other hand, the concentration time from Wu Zhou to Gao Yao becomes markedly short in the recent years due to the combined influence of the erosion of the river channel and other factors. Considering the ceaseless change of the river channel because of the natural and artificial effects, it's likely that we may made mistakes if we adopt the hydraulic method for channel flood-forecasting using the present channel's topographic datas. Whereas the hydrologic method only need hydrologic datas. Hence that if the stream condition is comparatively simple and we don't have the current channel's topographic datas then we should turn to the hydrologic method. Accordingly the combination of the hydraulic and the hydrologic method is necessary. In order to increase the accuracy of flood-forecasting, we'd better using real-time correction. In this thesis , two different means of real-time correction were discussed, they were the faded-memory least square method and the BP artificial neural network(ANN) method. And a analysis and comparison was made in this thesis.The results of the thesis proved that the combined use of the hydraulic and the hydrologic method in the flood-forecasting of the river channel between Wu Zhou and Gao Yao was feasible.