丹江口水库大坝加高后坝下游水温时空变化规律研究

Study on Temporal and Spatial Variation of Water Temperature in the Downstream of Danjiangkou Reservoir after Dam Heightening

南水北调中线工程水源地位于丹江口水库,丹江口水库大坝大坝加高,改变了原有的平衡模式,大坝下游丹江口-宜城河段水温发生了显著变化,水温变化直接影响河流生态系统。本文选用大坝加高前后典型水文站水温资料,采用对比分析,研究该河段水温变异特性及沿程分布。结果表明,丹江口水库大坝加高工程的运用对坝下游水温产生了一定的影响,黄家港水文站受大坝加高工程影响较大,年均水温呈现下降趋势,襄阳和余家湖水文站影响较小,黄家港水文站春、夏、秋三季平均水温有所下降,下降幅度最大的季节为夏季,下降值为4.9℃;下降幅度最大的月份是8月,下降值为5.5℃。

The water source of the Middle Route Project of South to north water diversion is located in Danjiangkou reservoir.After the dam of Danjiangkou reservoir is increased,the original balance mode has been changed.The water temperature of Danjiangkou Yicheng reach downstream the dam has changed significantly,which directly affects the river ecosystem.In this paper,the water temperature data of typical hydrological stations before and after dam heightening were used to study the water temperature variation characteristics and its distribution along the river.The results show that the application of the dam heightening project of Danjiangkou reservoir has a certain impact on the water temperature at the downstream of the dam.Huangjiagang hydrological station is greatly affected by the dam heightening project,and the annual average water temperature shows a downward trend.Xiangyang and yujiahu hydrological stations have less impact.The average water temperature of huangjiagang hydrological station in spring,summer and autumn has declined,and the season with the largest decline is summer,with a drop of 4.9℃;the month with the largest drop is August,with a drop of 5.5℃.