缓解水温失调问题的水库生态调控策略

Reservoir ecological regulation strategy to alleviate water temperature imbalances

水库蓄水改变了水温的时空分布,进一步引起库区生态系统紊乱及低温水下泄等生态问题,对土著鱼类的生长、繁殖产生不利影响。通过Delft3D模型建立三维水温模型,模拟了典型气象水文条件下的糯扎渡水库横向、纵向及垂向多个维度上水温的动态变化过程。在此基础上,结合下游鱼类生态水温需求,制定了以生态水温为目标的叠梁门分层取水方案;结合增殖放流要求,确定了糯扎渡库区土著鱼类(中国结鱼)最适宜放流的位置及时间。结果表明:不同年份叠梁门分层取水方案及增殖放流适宜的位置和时间均存在差异,综合典型年份水温需求以及叠梁门工程条件,制定了具有普适性的叠梁门分层取水规则,确定了适宜投放中国结鱼鱼苗的位置为小黑江支流河段、时间为8—9月份。本文可为制定缓解水温失调问题的水库生态调度策略提供一定的科学依据。

Reservoir impoundment has changed the temporal and spatial distribution of water temperature and caused ecological problems, such as ecosystem disorder and low-temperature underwater discharge in reservoir areas.This resulted in adverse effects on the growth and reproduction of indigenous fish.The 3-D water temperature model was established using the Delft3D model.The dynamic change process of water temperature in the transverse, longitudinal, and vertical dimensions of the Nuozhadu Reservoir under typical meteorological and hydrological conditions was simulated.Considering this context, and combined with the ecological water temperature demand of downstream fish, a layered water intake scheme of stacked beam doors with ecological water temperature as the goal was formulated.The most suitable location and time for releasing indigenous fish(Tor sinensis) in Nuozhadu Reservoir were determined by combining the requirements of the species involving breeding and release.It was shown in the results that there are differences in the layered water intake scheme of stop logs in different years and the suitable location and time for proliferation and release.The universal layered water intake rules for stop logs were formulated based on the water temperature demand in typical years and the engineering conditions of stop logs.The most suitable location for placing Chinese snakehead fry was the Xiaoheijiang tributary, preferably from August to September.A scientific basis for developing a reservoir ecological dispatching strategy to alleviate the water temperature imbalance may be provided by the results of this study.