基于经验相关的城陵矶日流量模拟模型研究

Research on Daily Flow Simulation at the Chenglingji Station Based on Empirical Correlations

基于洞庭湖水量平衡和长江干流对洞庭湖顶托作用,建立了一种经验的洞庭湖出口城陵矶流量逐日预报模型。首先建立了长江干流宜昌-枝城、枝城-监利流量的相关关系,推求枝城和监利流量;然后根据枝城站流量推求了三口分流量,根据鹿角水位或多输入单输出线性系统模型推求螺山流量;最后根据洞庭湖区鹿角水位以及长江干流监利站和螺山站的顶托作用求得城陵矶流量。模型计算结果与实测资料比较表明,不同水平年下城陵矶流量模拟的确定性系数均超过0.8,能为洞庭湖水文模拟提供新的方法。

An empirical model is developed to forecast the daily flow of Dongting Lake at Chenglingji Station based on the water balance of Dongting Lake and the backwater effect by the Yangtze River. Firstly,the correlations of Yichang-Zhicheng discharges,and Zhicheng-Jianli discharges are established to calculate the discharges of Zhicheng and Jianli Station. Then the discharge of three outlets are calculated from the discharge of Zhicheng Station,and the discharge of Luoshan Station is derived from the water level at Lujiao Station or by a multi-input single-output liner system model of Yichang-Luoshan discharges. Finally,the discharge of Chenglingji Station is derived by considering the upstream flow at Jianli station,water level of the Dongting Lake at Lujiao Station and the downstream backwater effect by Luoshan Station.Comparing the simulated results with measured data,the simulation efficiency of the discharge at Chenglingji Station is higher than 0.8 in different typical years. Results show that the model is reliable and can provide a new method for the hydrological simulation of Dongting Lake.