长江技术经济

分层取水是减缓新建大型水库下泄低温水对下游生态负面影响的关键工程措施。以长江流域青峪口大型水库为例，结合工程周边生态环境状况和水库调度运行方式，基于立面二维水温数学模型，模拟对比了不同分层取水方式对低温水的改善效果。研究结果表明：前置挡墙和叠梁门两种分层取水措施均能有效减缓高坝大库的低温水影响，降低对河流鱼类繁殖及生长的不利影响。从改善效果、工程调度运行和经济效益等多方面综合评估，在低水位运行期间采用前置挡墙措施更具优势。研究成果可为类似水文气候条件下大中型水库的分层取水技术选型、下游水生生物多样性保护提供参考。

Selective withdrawal structures have become essential engineering solutions to mitigate the ecological impacts of cold water released from large reservoirs on downstream ecosystems.This study evaluates two selective withdrawal methods at the Qingyukou Reservoir in the Yangtze River Basin.Using a two-dimensional vertical water temperature model and accounting for local ecology and operational schedules,we compare their effectiveness in mitigating cold water problems.Results demonstrate that both forebay retaining wall and a stop log intake effectively elevate downstream water temperatures,thereby alleviating the adverse effects on fish reproduction and growth.A comprehensive assessment,balancing improvement efficacy,operational practicality,and cost-effectiveness,identifies the forebay retaining wall as the superior option during low water level periods.The findings can provide a reference for selecting selective withdrawal technologies and protecting downstream aquatic biodiversity in large and medium-sized reservoirs under similar hydro-climatic conditions in other regions.