长江中游洪水调度研究（Ⅰ）：洪水调度的水文-水力学耦合模型

根据长江中游的实际特点,选择汊点分组解法求解河网矩阵方程,克服大型复杂区域内模型计算速度和整体性之间的矛盾。选择水文学-水力学模拟技术相耦合的集成措施,解决洪水调度中下边界难以确定的困难,在此基础上建立了洪水调度数学模型。模型在不同来水条件下均能取得较好的洪水调度模拟效果,能够根据调度原则,给出任意位置水位流量、蓄洪区进出洪量等详细信息,为防洪决策提供参考。

Numerical Modeling of Flood Control System in the Middle Yangtze River by Coupled Hydrological-hydrodynamic Approach

In the middle Yangtze River,the main stem,tributaries and lakes connected with each other forming a complicate water system.The outlet of the region shows complex stage-discharge relations because water exchange between different sections varies with flood synthesis.These features bring difficulties for simulation of flood control system operation,which relies on the accurate water level forecasting and the operation of more than twenty flood detention areas located both alone the main reach and Dongting Lake area.The two basic flood routing approaches,"hydrologic routing" and "hydraulic routing" are compared,and hydrologic approach is employed to give downstream boundary condition for hydraulic method.By means of integrating the two approaches,a model is developed to give information of water level reduction and inlet and outlet process of detention areas.Calibration of the model shows that it can overcome the proper difficulties,and its application under the scenario of 1954 and 1996 flood is efficient and satisfying.