三峡水库提前蓄水对中华鲟产卵的影响

Impact of Three Gorges reservoir operation with ahead impounding water on Acipenser sinensis spawning

以葛洲坝至庙咀江段中华鲟主要产卵场为研究区域,采用结构有限体积法求解该江段的二维水动力学模型,模拟水库正常蓄水与提前蓄水方案下该区域的流场分布。在此基础上,综合考虑中华鲟产卵对流速、水深以及底质的喜好,采用物理栖息地模型计算不同流量序列下栖息地加权可用面积(Weighted Usable Area,WUA)的大小,并且得到WUA与流量的关系曲线。分析结果表明:三峡水库采用提前蓄水方案能够显著增加中华鲟产卵栖息地的WUA,减轻蓄水对中华鲟产卵的不利影响,并且得到中华鲟产卵的适宜流量范围为13000～19000m3/s。该研究结果为葛洲坝下游中华鲟的保护提供参考依据,同时也为三峡制定生态调度方案提供一种新的思路。

This paper focuses on a study of the main spawning grounds of Acipenser sinensis in the reach from Gezhouba to Miaozui. A two-dimensional hydraulic model was solved with a finite-volume method and the flow field was simulated for normal impoundment scheme and ahead impoundment scheme. By combining this model with a physical habitat model and considering the spawning preference velocity, water depth and substratum, weighted usable area （WUA） of the habitat was calculated for different flow series and a relationship between WUA and flow was established. The results indicate that the ahead impoundment scheme is beneficial to the spawning and the flow of 13000 - 19000 m3/s is optimal. This work provides a support to Acipenser sinensis protection and ecological operation of the Three Gorges reservoir.