上游水库水温情势变化对中华鲟产卵江段水温的影响

针对三峡水库蓄水运行后中华鲟自然产卵期逐渐推迟的问题,对影响中华鲟繁殖关键要素水温的因素开展研究。基于三峡大坝及葛洲坝上下游典型断面的水温及气温实测资料,分析了三峡水库蓄水后10年(2003—2012年)的水温变化情势和影响葛洲坝下游中华鲟产卵江段特定时段水温的原因。结果表明:三峡水库蓄水后库区在10月水温高于蓄水前,对下游中华鲟产卵江段水温产生直接影响;局地气温变化与水温情势变化密切相关,是引起中华鲟产卵江段水温上升的根本原因,对水温上升的贡献度约为61%。

Effects of temperature variation at upstream of the Three Gorges Reservoir on Chinese sturgeon spawning reach

Focusing on the problem that the spawning time of the Chinese sturgeon has been delayed to November due to the impoundment of the Three Gorges Reservoir(TGR), this paper studied one of the key factors, water temperature, that influences the reproduction process. Based on the measured water temperature and meteorological data at typical cross-sections upstream and downstream of the Three Gorges Dam and the Gezhou Dam, water temperature variation during the first decade after the impoundment of TGR(2003-2012)and its effects on water temperature characteristics in the Chinese sturgeon spawning reach located in the downstream of Gezhou Dam were analyzed. The result shows that after the impoundment of TGR, water temperature in the reservoir is higher than before, having substantial effects on the downstream reaches. Local air temperature variation is closely related with the water temperature variation and it can be a fundamental reason for water temperature rise in the spawning reach, accounting for a contributing degree of about 61%.