二滩水库水温结构及其影响因素研究

采用三维水温模型，对二滩水库水温结构进行数值模拟，模拟了二滩水库水温结构特征，发现二滩水库水温垂向分布呈现单温跃层和双温跃层两种型式。研究了水库水温结构变化的影响因素，表明影响二滩水库水温结构的因素主要有气象要素、库区来水流量和水体温度、水库出流位置及流量大小等。夏季二滩水库随着上游来水水温的增大，水库水温相应增加，但在温度异重流和紊流扩散的双重作用下，仅是水库中层均温层水体温度同步增加。随着二滩水库大坝出水位置的改变，库区流态发生变化，随着出水口位置的下移，水库来水和出流形成的纵向水流随之向库底下潜，水库中层均温层垂向厚度增加，对库底水温的干扰增强。

Research of Water Temperature Structure and Influencing Factors in Ertan Reservoir

Three dimensional water temperature model of reservoir was proposed in order to simulate water temperature structure in Ertan reservoir. The results show that water temperature distribution of Ertan reservoir is single thermocline or double thermocline, and the main influencing factors of water temperature structure are weather conditions, flow rate and water temperature of inflow, outflow position and discharge. It is found that water temperature of reservoir in summer accordingly rises as inflow water temperature rises, and only the temperature of uniform temperature layer of reservoir mid increases synchronously due to density current and turbulent diffusion in reservoir. When outflow position of Ertan Reservoir is changed, the flow regime of reservoir will vary. Along with down-shift of outflow position, longitudinal stream formed by reservoir inflow and outflow accordingly descend to the bottom of reservoir, the thickness of uniform temperature layer of reservoir mid increase, disturbance of temperature of the bottom of reservoir is enhanced.