中文摘要：

三峡工程蓄水使得下游长江河道水温情势发生显著变化,并对下游生态环境产生重要影响。基于宜昌水文站14年的实测资料,采用纵向一维水温模型模拟分析了宜昌至监利300 km河道水温变化过程,探讨了不同蓄水期三峡工程下泄水温变化对坝下鱼类产卵场的影响程度。结果表明：1三峡工程蓄水后宜昌断面水温出现了平坦化及延迟现象,低温水和高温水效应明显;175 m蓄水期宜昌断面4月、12月,水温分别较蓄水前改变-4.3℃、3.7℃。2三峡工程的运行使得下游河道水气热交换量发生变化,但干流流量较大使得水温沿程恢复效果较弱;工程调蓄对坝下河段的影响占主导作用,三峡工程调蓄对监利断面4月、12月存在-3.2℃、3.0℃的温度影响。3三峡工程蓄水后,宜昌中华鲟产卵场冬季20.0℃的水温出现时间推迟1-4旬,监利四大家鱼产卵场春季18.0℃的水温出现时间推迟1~3旬,并随着蓄水位的抬升,推迟幅度逐渐加大。

英文摘要：

The Three Gorges Reservoir has changed the water temperature trend on downstream waters of the Yangtze River and has an important impact on downstream ecological environment. Based on the measured data of the Yichang hydrological station on Yangtze River during a period of 14 years（ 2000—2013）,the one-dimensional longitudinal temperature model was used to analyze the temporal and spatial variation of water temperatures of the expanse of 300 km along the river,from Yichang to Jianli,which occurred as a result of the Three Gorges Reservoir Reservoir. The impact on spawning grounds due to water temperature variation was also discussed in different impoundments. The research results show the following： 1 As a result of the Three Georges Reservoir,there was a phenomena of planarization and delay of the water temperature process in Yichang. It is also evident that the discharged water is of a lower temperature during the summer and higher temperature in winter on downstream. Compared with the natural water temperature,the water temperature in Yichang changed to-4. 3 ℃ in April and 3. 7 ℃ in December during the period of the 175 m stage. 2 As a result of the operation of this project,the water-air heat exchange on downstream river waters has also experienced much change,and the relatively strong flow has caused the water temperature of the nature status along the river to recover slowly. The dam also plays a decisive role in regulating the downstream water temperature. The water temperature of Jianli changed-3. 2 ℃ and 3. 0 ℃ in April and December respectively. 3 After the Three Gorges Reservoir was put into operation,the original water temperature in the Chinese sturgeon spawning grounds of Yichang which reached 20. 0 ℃ in winter began to experience a delay of 10—40 days. The water temperature of 18. 0 ℃ in the Four Major Chinese Carps grounds of Jianli in spring time also experienced a delay of 10—30days. In accordance with the rising level of Three Gorges Reservoir,the trend of the delay will