感潮河道区间入流反分析

区间入流是影响水动力模型精度的重要因素,实际的区间径流情况复杂难以量化。从反问题的角度出发,由基本方程导出区间入流校正量的解析表达式,应用数值离散方法,得到节点水位与区间入流的响应函数,根据实测的潮位资料建立区间入流的迭代求解方法。数值实验验证了方法的可行性,反问题的计算值与真值非常接近,模拟的确定性系数达到0.996。该方法应用于长江下游大通至镇江河段的水动力模型实例计算,得出了概化的区间入流过程,提高了模拟精度,验证了方法的有效性。

An inverse analysis of local inflows in tidal river networks

The local inflow is an important factor affecting the accuracy of hydrodynamic models, but its value is difficult to determine and quantify in real-world applications.From the viewpoint of inverse problems, a method is proposed to determine the local inflow.Firstly, the continuity equation is integrated along the reach to have the analytic expression of inflow correction, and then the response function between the nodal stage and the local inflow can be obtained by numerical discretization.Finally, based on observed tidal data, the local inflow is evaluated by the iterative algorithm.A numerical experiment is conducted to validate the feasibility of the proposed method.Excellent agreement is obtained between the inverse values and the real ones as revealed by the deterministic coefficient of 0.996.The method is applied to the hydrodynamic modeling of the reach from Datong to Zhenjiang in the Yangtze River.The generalized process of local inflows in the reach is obtained and further refined.The result demonstrates the validity of the method.