基于图论的韩江流域水库群生态调度

采用水文学方法计算了韩江流域干支流重要控制断面的生态流量目标；基于图论原理，根据流域内干支流水系特征、重要水利工程和控制断面分布情况构建了韩江流域河网图模型；考虑河段区间来水、河道外取水、引调水等边界条件以及流域水库群水量调蓄作用，开展了河网水量平衡计算，确定了河网节点流量。通过计算水库坝址所在断面的天然生态基流，提出了耦合最小生态下泄流量要求的水库常规调度规则；借鉴大系统聚合-分解思想，提出了韩江流域河网图模型迭代优化求解思路；通过选取不同典型年来水过程，评估了常规调度情况下控制断面生态流量保障程度，并在此基础上进行优化调度，分析流域水库群生态调度保障潜力。结果显示，耦合最小生态下泄流量要求的水库常规调度规则能够让水库在独立运行的情况下，基本保障不同来水条件下的控制断面生态流量需求；韩江流域水库群可通过开展联合优化调度满足控制断面生态流量需求；基于图论方法开展流域水库群生态调度具有可行性和实用性。

Multi-reservoir ecological operation based on graph theory in the Hanjiang River Basin

The objective ecological flows in vital controlled sections in main stream and tributaries of the Hanjiang River Basin are calculated with hydrological methods. Based on graph theory, the river network graph model of the Hanjiang River Basin was constructed according to the characteristics of the river system, the distribution of important water conservancy projects and control sections. Flow at each node of the river network was determined by carrying out water balance calculation of river network, which takes interval flow, water intake and water diversion as well as water regulation effect of multi-reservoir system into account. By calculating the natural ecological base flow of the sections where reservoir dams are sited, the conventional reservoir operation rules coupling the requirements of minimum ecological discharge are put forward. Referring to the idea of aggregation and decomposition of a large-scale system, the idea of iterative optimization of river network model of the Hanjiang River Basin is put forward. The secured ecological flow level under conventional regulation is evaluated with the flow processes in typical years. On this basis, optimal operations are conducted and the potential of secured ecological operation on multi-reservoir in the basin. The results show that reservoir conventional operation scheme coupled with the minimum discharge requirements can basically secure the ecological flow demand at the control sections with various flow processes, under the condition of independent operation in reservoirs. Reservoirs in the Hanjiang River Basin can meet the ecological flow demand at the control sections through optimal joint operation. Carrying out multi-reservoir ecological operation based on graph theory is feasible and practical.