考虑未来径流变化的丹江口水库多目标调度规则研究

气候变化会引起水文循环和入库径流变化,改变当前水库各调度目标的制约关系,影响水库调度规则。考虑未来径流变化对水库调度的影响,推求相应的水库多目标调度规则对未来水库管理有着重要意义。本文以丹江口水库为例,建立了考虑未来径流变化的多目标优化调度模型。以全球气候模式(GCM)模拟结果作为未来气候变化情景,将降尺度处理后的气象要素输入可变下渗能力(VIC)模型预测丹江口水库未来入库流量序列,采用非支配排序遗传算法(NSGA-II)算法推求多目标调度函数集,结合设计的水库调度图得出兼顾丹江口水库供水和发电的多目标调度规则。通过对比分析发现,目前的调度规则不能很好地适应未来径流变化,而考虑未来径流变化的多目标优化调度规则能有效协调供水和发电的矛盾。以发电和供水为主两种不同调度规则对各目标的影响存在差异,其中主要考虑供水的调度规则能显著提高(18.7%)水库的供水量。

Multi-objective operation rules for Danjiangkou Reservoir under future runoff changes

Climate change alters hydrologic cycle and reservoir inflow and brings about conflicts between different objectives in reservoir operation. A significant issue in reservoir management is how to adjust reservoir operation rules accordingly through research considering the possible future changes in runoff and hydrologic cycle. In this study, we have developed a multi-objective optimization model for operation of the Danjiangkou Reservoir considering possible future runoff changes. To predict future runoff in this model, the results of the global climate model (GCM) are downscaled by a statistical downscaling model and then inputted into a calibrated variable infiltration capacity (VIC) model. And multi-objective operation rules can be derived using a non-dominated sorting genetic algorithm II (NSGA-II) method, combining the design operating rule curves with the predicted future inflow series and considering the tradeoff between power generation and water supply. Results show that this reservoir needs to modify its existing operation rules to adapt to the future runoff changes and the multi-objective operating rules so obtained are effective in mitigating the conflict between water supply and power generation and improving comprehensive water utilization. In general, power generation-oriented and water supply-oriented rules will produce different results in the objectives, among which the water supply-oriented rule is able to increase water supply capacity significantly (by 18% in the Danjiangkou case).