Author(s): Shijie Zhang; Junping Yan; Qiang Du; Hongwu Tan; Guoqiang Li; Yisi Zhuge; Xiao Yu
Linked Author(s): Qiang Du
Keywords: Large reservoirs; Water temperature structure; Vertical water temperature profile; Spatiotemporal differentiation. ℃. W ang
Abstract: water temperature in reservoir is heterogeneously distributed in 3D space, has a complex structure of dynamic change with the time, and exerts a profound influence to the ecological system in the reservoir and downstream area. Thermal stratification in large reservoir and environmental problems from the release of low-temperature water are quite prominent. Research on the law of spatiotemporal differentiation in the water temperature structure in large reservoirs in inland different geographical locations is significant to correct evaluation of environmental influence from reservoir project and scientific management of reservoir. In this paper based on the statistical analysis and research of field measurement on water temperature of 26 large reservoirs in China, the following conclusions are drawn. (1) Large reservoirs whose water exchange coefficient is less than 10, regulation performance is above seasonable regulation, and water depth is above 70m, belong to thermal stratification type. (2) The vertical water temperature profile is classified as 6 types, including hybrid structure, dual-thermocline structure, upper-layer single-thermocline structure, middle-layer single-thermocline structure, thermal inversion structure, and the structure influenced by sediment. (3) Vertical water temperature profile type in different reservoirs is distributed regularly according to four Chinese geographical zones during a year. (4) The surface water temperature isoline in different reservoirs gradually turns towards northwest during Spring and Summer, and towards southeast during Autumn and Winter. (5) The annual variation trend of the bottom water temperature in different reservoirs is similar.
Year: 2013