具有行蓄洪区的复杂水系实时洪水预报研究

Real-time flood forecasting for complex watershed with flood diversion and flood retarding areas

建立确定和随机相结合的预报模型对复杂水系的实时洪水预报进行研究。确定性模型采用分布式概念性模型进行流域流量过程预报;基于马斯京根法、水文水位法与扩散波非线性水位法,构建河道流量和水位模拟的综合法对河道以及行蓄洪区的洪水进行预报。随机模型采用基于误差自回归的时变遗忘因子最小二乘递推法对误差进行实时校正。以淮河鲁台子以上流域为例,具有行蓄洪区的干流洪水采用河道流量和水位模拟的综合法与实时校正模型按节点有机结合的方法进行预报。预报模型在2007年的大洪水预报中得到了检验,取得了较高的精度。

An integrated approach of combining deterministic and stochastic models is applied to real-time flood forecasting for complex watersheds.The deterministic model forcasts watershed yield by adopting a distributed hydrological conceptual model,and simulates flooding runoff and water level for river channel with flood diversion and flood retaring areas by adopting the Muskingum routing method,the hydrological method of water level simulation as well as the nonlinear water level method of diffusion wave.Real-time error is corrected by the stochastic model using time-variant forgetting factor and least-square method.For the test case of the middle reaches of the Huaihe River between Wangjiaba and Lutaizi,channel stations are used to dynamically link the channel flood model and real-time correction model,and the flood of the watershed,main river as well as flood diversion and flood retarding areas is forecasted.A good forecasting accuracy of the 2007 Huaihe river flood was achieved.