【摘要】 洞庭湖的水情是长江和四水共同作用的结果,三峡蓄水运行必将导致洞庭湖的水情变化.本文利用BP神经网络对洞庭湖出口城陵矶站的水位过程进行模拟,以区分城陵矶水位变化中三峡的影响分量.模型训练阶段以三峡出库日均流量、洞庭湖四水合成日均流量为输入,城陵矶站的日水位过程为输出,应用阶段用三峡入库流量代替出库流量,从而还原自然状态下的城陵矶水位变化过程,最后通过比对确定三峡蓄、泄水对洞庭湖水位变化的影响.计算结果表明,三峡蓄水对洞庭湖水位产生了较大的影响,2006年蓄水使城陵矶水位平均下降2.03m,最大降幅3.30m,2009年蓄水使城陵矶水位平均下降2.11m,最大降幅3.12m.三峡蓄水对秋季城陵矶水位的影响不容忽视.更多还原

【Abstract】 Hydrological regime of Lake Dongting is the overlap of discharge from Yangtze River and four other inlets around the lake(i.e.Xiang,Zi,Yuan and Li Rivers).The operation of the Three Gorges Reservoir(TGR) inevitably disturbs this hydrological regime.In this paper,the water level processes of Chenglingji Station(outlet of Lake Dongting) were simulated by using BP neural networks,to evaluate the independent proportion/weight of water level change caused by the operation of the TGR.In the training phase,the average daily outflow discharge of TGR and the synthetic discharge of other four inlets were chosen as inputs,and the water level of Chenglingji Station as output.In the implementation phase,the outflow discharge of TGR was replaced with the inflow to simulate the water level process without regulation of TGR.The results indicate that significant impacts have been introduced due to the runoff regulation of the reservoir.The water level dropped 2.03m in 2006 and 2.11m in 2009 during the reservoir storage period,and the extreme drop was up to 3.30m and 3.12m,respectively.In view of its potential impacts on the structure and function of lake wetlands,proper attention should be paid to this occurrence.更多还原