中文摘要：

水库水温变化是评价环境影响的主要指标之一。为评估三峡水库蓄水后水温变化，本文采用数学模型分析了库首105km范围内的水温分布规律。结果显示：（1）三峡水库蓄水后水温变化对气象条件的响应变慢，沿程温差有所加强，在升温期上游水温高于下游；（2）在给定的水文气象条件下，库首江段在4-6月份将会出现弱分层，垂向温差在1-2℃。采用蓄水前后的实测资料对数值预测结果进行了分析，论证了本文预测结果的合理性。

英文摘要：

Temperature is one of the major indexes in environmental impact assessment. In order to estimate the influence on water environment due to the rise of the water level, the temperature distribution is studied deeply at the area about 105 km long in Three Gorges Reservoir（TGR） by means of mathematical model. The results show that： （1） since the temperature variation response will be slowly to meteorological condition, the water temperature of the upstream will be higher than the downstream in the temperature increasing period. （2） there will be a weak stratification from April to June in TGR when the reservoir controls normally under certain hydrological and meteorological conditions, the vertical temperature difference is only limited within about 1-2℃ in TGR. The results are verified based on the data observed after and before the reservoir stores water, which show the numerical simulation results are reliable.