中文摘要：

梯级开发将引起河段水温累积影响,为研究龙头水库方案调整而引起的水温累积影响的新变化,以黄河上游某河段为例,基于河段上各水文站的观测资料和龙羊峡、刘家峡的实测资料,采用三维水温模型预测各梯级水库的水温分布,对比各梯级的水温累积影响。研究结果表明：龙头水库兴建使下游水温呈现冬季升高和夏季降低的均化过程,较天然状况存在滞后性;水电站B和D对水温累积影响呈现协同增大效应,水电站F呈现削弱减小效应;在暖季龙头水库方案变化对梯级末端仍有影响。研究结果可为河段梯级规划环境影响评价提供科学依据。

英文摘要：

The cascade development of river basin can bring in new changes to the accumulative effects on water temperature.With a certain river section of the upstream of the Yellow River to the example and based on the observed and measured data of each hydrological station as well as the real measured data of the Longyang Gorge and the Liujia Gorge,3-D water temperature model is adopted to predict water temperature distribution in each cascade reservoir and to contrast the effect of water temperature cumulative effect of each cascade reservoir.The research results indicate that the construction of the uppermost reservoir makes the downstream water temperature appear to have the equalized process of water temperature rising in winter and lowering in summer,and there exists a lag behind the natural cycle.Hydropower stations B and D have had the coordinative enlargement effect upon water temperature accumulation,but hydropower station F appears to have the weakening and decreasing effect,and the uppermost reservoir program adjustment in the warm season may still have some effect upon water temperature of the ending cascade reservoir.Accordingly,the research findings can provide the scientific basis for environmental impact evaluation of river section cascade development and planning.