论文部分内容阅读
为揭示三峡蓄水对局地气候的影响,利用TRMM 3B42卫星降水产品分析了三峡蓄水前后(以2003年为分界)库区的局地降水变化。分析表明,蓄水以后,库区西北部年累积降水量增加,东南部年累积降水量减少,这种降水变化是大尺度上降水变化的区域体现。蓄水对干流附近降水产生了一定影响,干流站点间降水量差别增大,但整个大库区平均的年累积降水量无明显变化。蓄水之后的降水变化具有季节差异。冬季几乎整个库区的降水量都有所增加;春季降水量在干流的上游个别地区和下游减少,中游增加;夏季除库区下游部分地区外,大部分库区降水量有所减少;秋季,库区的上游和中游降水增加,下游降水减少。区域平均的季节降水量无明显年际趋势。结果表明,三峡蓄水带来的降水变化空间尺度只局限在近库区,对整个大库区降水变化的影响可忽略不计。
In order to reveal the impact of the impoundment of the Three Gorges Reservoir on the local climate, the local precipitation changes in the reservoir area before and after the Three Gorges impoundment (stratified by 2003) were analyzed using the TRMM 3B42 satellite precipitation product. The analysis shows that after the water storage, the annual cumulative precipitation in the northwestern part of the reservoir area increases, and the annual precipitation in the southeast decreases. This kind of precipitation variation is a manifestation of the large-scale precipitation changes. Impoundment of water has a certain impact on the precipitation near the mainstream, the difference between the precipitation increases in the mainstream, but the average cumulative precipitation in the entire reservoir area no significant change. There is a seasonal difference in precipitation changes after water storage. Precipitation increased in almost all the reservoir area in winter; the precipitation decreased in some areas and downstream in the upper reaches of the mainstream in the spring and increased in the middle reaches; the precipitation decreased in most of the reservoir areas except in the area downstream of the reservoir in summer; in autumn, Precipitation in the upper reaches and middle reaches of the reservoir area increased, while precipitation in the lower reaches decreased. There is no obvious interannual trend in the regional average seasonal precipitation. The results show that the spatial scale of the precipitation change brought by the Three Gorges Reservoir is confined to the near reservoir area and the impact on the precipitation in the whole reservoir area is negligible.