丹江口水库大坝加高对汉江干流水温影响评价

为探究丹江口水库大坝加高对汉江干流水温的影响，采用汉江干流白河站、黄家港站和襄阳站实测水温资料，基于改进的河流水温变化评价指标，分析了大坝加高前后汉江水温变化趋势，量化评估了水库下游河道水温的变化程度。结果表明：丹江口水库大坝加高显著改变了汉江中游水温情势，坝下河段水温极值变幅指标呈下降趋势，均化程度逐年加深，黄家港站最高、最低水温的出现日期均向后推迟，存在“滞冷”和“滞温”现象；水温情势的改变程度与距离密切相关，距离大坝较近的黄家港站水温情势变化明显，水温集中期相较于大坝加高前滞后约23 d;距大坝较远的襄阳站水温情势变化较小。

Assessing impacts of Danjiangkou Dam heightening on water temperature in main stream of Hanjiang River

To assess the impacts of the Danjiangkou Dam heightening on water temperature in the main stream of the Hanjiang River, the measured water temperature data of the Baihe, Huangjiagang and Xiangyang stations in the mainstream of the Hanjiang River was analyzedand the variation degree of water temperature in the lower reaches of the reservoir was quantitatively evaluated based on the improved evaluation indicator values for river water temperature variation. The results show that the Danjiangkou Reservoir heightening has significantly changed the hydrological regime in the middle of the Hanjiang River. The extreme variation value of water temperature under the dam shows a downward trend, and the degree of homogenization increases year by year. The date of the maximum and minimum water temperature at the Huangjiagang station has been postponed, indicating the phenomenon of cold and warm stagnation. The change degree of water temperature regime is closely related to the distance. The Huangjiagang station is closer to the dam, and its water temperature regime changes obviously, and the water temperature concentration period lags about 23 days compared with that before the dam heightening. The Xiangyang station far away from the dam has little water temperature variation regime.