中文摘要：

水库水温对于生态系统具有决定性的影响。对紫坪铺水库库尾天然河道、坝下进行逐时连续观测,分降温期和升温期对紫坪铺水库进行两次全库区观测,结合数值模拟对观测结果进行了分析。紫坪铺电站调节导致下泄水温呈现冬季高温和春季低温现象,下泄水温变幅远低于入库水温变幅。数值模拟较好地计算了库尾水温无分层结构到坝前分层结构的发展过程,模拟出在入流、出流和水气界面热交换影响下垂向温跃层的形成和发展。水库淤积和发电进水口附近的三维流场效应导致枯期计算水温系统性偏低于实测水温。

英文摘要：

Water temperature in reservoirs has significant impact on ecosystem. In order to study the water temperature change of Minjiang River,a series of water temperature observations and researches of Zipingpu Reservoir were conducted,which included continuous observations in the natural river upstream and downstream of the dam. Meanwhile,observations in the reservoir were carried out in the temperature rising period and decreasing period,respectively. Combined with numerical simulation,the prototype observation data was analyzed. The regulation of Zipingpu power station led to the phenomenon that the discharge water temperature was high in winter and low in spring. In addition,the discharge water temperature variation is much lower than the storage temperature changes. The development process of water temperature stratification from low intensity in the reservoir tail to high intensity in front of the dam was well predicted by numerical simulation,as well as the formation and development of vertical thermocline that were affected by inflow and outflow of the reservoir and heat exchange at air- water interfaces. However,due to reservoir sedimentation and three- dimensional effect of flow field near the reservoir outlet,computed values of temperature in dry season were lower than the observed data.