溪洛渡水库分层取水对向家坝库区水温的影响分析

Analysis of Effect of Stratified Water Withdrawal in Xiluodu Reservoir on Water Temperature in Xiangjiaba Reservoir Area

为了探究上游溪洛渡水库分层取水对下游向家坝库区水温的影响,基于历史水文数据,分析向家坝建库对河道水温的影响,结合率定好的CE-QUAL-W2模型,设置溪洛渡水库分层取水与不分层取水两种计算工况,分析2019年溪洛渡水库分层取水对下游向家坝库区水温变化过程的影响。结果表明,向家坝水库蓄水后使坝下河道水温达到18℃的时间滞后50 d,向家坝坝下河道水温受支流水温影响较大;2019年上游溪洛渡水库分层取水在4~5月最高可使下游向家坝库区表层水温升高1.0℃,其影响沿程逐渐减弱,至绥江县城完全消失;分层取水使下游向家坝库区4~5月水温结构明显改变,4~5月下泄水温明显提高,最大可提高0.48℃。研究结果可提高对叠梁门分层取水效果的认识,并为后续生态调度提供科学依据。

In order to investigate the influence of stratified water withdrawal in the Xiluodu reservoir on downstream water temperature in the Xiangjiaba reservoir area,historical hydrological data was used to explore the impact of the Xiangjiaba construction on river water temperature.By integrating the calibrated CE-QUAL-W2 model,this study analyzed the effects of stratified water withdrawal in 2019 on the variations of water temperature in the downstream Xiangjiaba reservoir area.The results show that the Xiangjiaba reservoir caused a 50-day delay in reaching 18℃,and the water temperature in the downstream reach of the Xiangjiaba was greatly influenced by the temperature of tributary inflows.Stratified water withdrawal in 2019 resulted in a maximum surface water temperature increase of 1.0℃in the Xiangjiaba reservoir area during April and May.However,this influence gradually diminished along the downstream,completely disappearing in the Suijiang County.The stratified water withdrawal significantly altered the water temperature structure in the downstream Xiangjiaba reservoir area during April and May,with a noticeable increase in the outflow temperature,reaching a maximum of 0.48℃.These findings contribute to a better understanding of the effects of stratified water withdrawal and provide a scientific basis for subsequent ecological scheduling.