由于南四湖错综复杂的地形变化和湖盆特征，若采用传统一维总流计算法进行湖内开挖疏浚工程的水力计算，将会影响输水工程的可靠性。因此，以南四湖万分之一地形图（CAD版）和卫星遥感影像资料为基础，创建了南四湖深度平均平面二维水流数学模型体系，并进行了模型验证。在南四湖调水设计方案条件下，开展了上、下级湖二维流场的数值模拟试算，确定了同时满足正常设计和特殊干旱运行控制点水位要求的最小规模开挖方案。流场分析表明，南四湖输水时上、下级湖全湖区在水位差的作用下呈现由南向北流场方向的单一性特点；主航道平均流速为0.12 m/s，一般高于非主航道区一个数量级左右；输水主航道平均流量比例为61.5 %，最大可承担88.9 %，说明南四湖湖内主航道承担着主要输水功能。

Due to the complex terrain changes and characteristics of Nansi Lake Basin, the reliability of water transfer project can be affected if the traditional one-dimensional total flow method is used in the hydraulic calculation of dredging project in the lake. In this study, a depth-averaged two-dimensional mathematical flow model system of Nansi Lake was created and verified on the basis of 1/10000 scale topographic map (CAD version) and satellite remote sensing images of Nansi Lake. Under the conditions of design water transfer scheme, the flow fields of the upper and lower Nansi Lake were simulated using the two-dimensional mathematical model. The dredging program with the smallest amount of excavation was determined in order to meet the requirements of water level at control locations under both normal design and special drought conditions. Analysis of the flow field results indicated that the flow field in the whole lake, both in the upper and lower lakes, showed solo-directional feature from south to north during the process of water transfer. The average flow velocity in the main channel was 0.12 m/s, generally about one order of magnitude higher than that in the non-main channel regions. The main channel of Nansi Lake played the major role in water transfer as its average flow rate accounted for 61.5% of the total flow rate and its maximum capability can reach 88.9%.

山东省南水北调工程建设指挥部资助(2003-01)