基于洪水脉冲历时的三峡水库生态调度研究

A Study of Three Gorges Reservoir Ecological Operation Based on Flood Pulse Duration

三峡工程为我国带来了巨大的经济效益,但同时水库也改变了下游天然的水文情势,造成如四大家鱼等鱼类资源急剧下降。为探究水库运行对四大家鱼产卵的影响,根据洪水脉冲理论,提出与洪水脉冲特征相关的若干个水文指标,并根据这些指标对水库下游宜昌站每年5-7月实际径流过程进行统计,经Mann-Whitney U非参数检验后找出产生显著性变化的洪水平均涨、落历时等指标。基于此建立水库多目标生态调度模型,根据历史洪水规律在模型中加入洪水脉冲历时控制方法,计算不同权重分配下的水库最优发电效益及洪水最优涨落历时,模型结果显著增加了洪水涨落历时且对发电效益影响甚微。延长洪水涨落历时为现阶段的水库生态调度提供了一种新的思路,但对四大家鱼产卵的实际促进作用仍需实践检验。

The three gorges project has brought enormous economic benefit to our country. Meanwhile it has changed the natural hydrological regime downstream, resulting in the drastic decline of fish resources like four major Chinese carps. To explore the effect of reservoir operation on the spawning of Chinese carps, this paper develops several hydrological indexes concerning flood pulse characteristics based on flood pulse theory, and does statistics of the actual flow process from May to July every year at Yichang Station, finding out the significant changes in flood average rise and fall duration through Mann-Whitney U non-parametric test. Based on above, this paper establishes multi-objects ecolog- ical operation model, adds the way of controlling the flood duration in the model according to historical flood discipline, calculates the optimal power generation benefit and optimal flood duration by using the wolf pack algorithm under different weight distributions. The result of the model increases the flood rise and fall duration significantly and has a little effect on power generation benefit. The extension of flood rise and fall duration provides a new perspective of current reservoir ecological operation, while the practical effectiveness of improving the spawning of four major Chinese carps still needs to be examined.