关键词: 三峡工程, 一维水流水温模型, 水温变化

Abstract: Researches on the influencing factors of water temperature variation near downstream Gezhouba dam would be conducive to understand the nature of water temperature variation, and is of great significance for the protection of Chinese sturgeon spawning grounds. In the present research, one-dimensional mathematical model of water flow and temperature together with the overall heat budget balance is adopted to preliminarily research this issue. Results reveal that the water temperature near downstream Gezhouba dam is mainly affected by the water temperature in the Three Gorges Reservoir; while other factors such as the inflow heat from Cuntan, the outflow heat from Three Gorges Dam and the operation mode of Gezhouba hydropower station have relatively less impacts. To be specific, net radiation heat and vaporization heat dominated the yearly variation of water temperature in the reservoir both before and after the operation of TGP, but the contribution of air-water heat conduction increased remarkably after the TGP operation. In November, particularly, heat conduction was the main influencing factor before and after TGP, but after the operation of TGP with the raising of impoundment level, the proportion of radiation heat and vaporization heat increased obviously, whereas heat conduction, inflow heat from Cuntan, and outflow heat from Three Gorges Dam gradually weakened. The operation of TGP have impacts on the contribution of each factor, hence affecting the water temperature in downstream Gezhouba dam.

Key words: Three Gorges Project, one-dimensional model of water flow and temperature, water temperature variation