对区域降水时空分布变化趋势的分析可以为区域水资源的合理管理与利用提供参考,利用三峡库区及周边共27个气象站点的逐月降水数据,通过线性倾向统计、滑动平均两种方法对三峡库区1951-2012年年均、雨季、旱季降水与降水日数的变化趋势进行了研究,并利用多元回归分析对三峡库区内年均降水量和降水日数的空间分布情况进行了分析.结果表明,三峡库区近62 a来的年均、年均雨季、年均旱季降水量和年均降水日数都有减少趋势,年均降水日数的减少趋势比降水量的减少趋势更加显著,并且降水日数明显减少的时间要早于降水量,这表明平均每个降水日内的降水量呈增加的趋势,也即短历时强降雨事件呈增加趋势.多年平均降水量与经度(P=0.081)、纬度(P=0.367)的相关性均不显著,而与海拔高度(P=1.90E-4)达到极显著相关水平.多年平均降水日数与经度(P=0.539)相关系不显著,而与纬度(P=8.77E-4)和海拔高度(P=1.82E-12)均达到极显著相关.降水量和降水日数均与海拔高度达到极显著正相关,可以利用海拔高度相对准确预测研究区内年降水和降水日数的空间分布特征,海拔每升高100 m,对应降水量与降水日数分别约增加30 mm、4.5 d.%Analysis on the spatial and temporal distribution of precipitation could provide useful reference for the management and utilization of regional water resources. By using monthly precipitation data of 27 weather stations within and around Three Gorges Reservoir Area (TGRA), the changing trend of precipitation in TGRA from 1951 to 2012 (62 years) were analyzed through linear tendency estimation and moving average methods. The spatial distribution of precipitation and total number of precipitation days were also analyzed through multivariate regression method. The results showed that the average annual precipitation, average annual precipitation in the rainy season, average annual precipitation of the dry season and average annual rainy days all presented a decreasing tendency. The average annual rainy days decreased more significantly than the average annual precipitation, and the start time of average annual rainy days was earlier than that of average annual precipitation, which indicated that the precipitation depth in a rainy day would increase, which also means that there will be more intensified rainstorms. The average annual precipitation was found has no significant correlations with longitude (P=0.081) and latitude (P=0.367), while has a strong correlation with the altitude (P=1.90E-4). Furthermore, the average annual rainy days were also found to have a strong positive correlation with both the latitude (P=8.77E-4) and altitude (P=1.82E-12), while has no significant correlation with longitude (P=0.539). Owing to the strong positive correlations between altitude, precipitation and the rainy days, the altitude could be possibly used for predicting the spatial distribution of precipitation and rainy days. According to the forecast model, precipitation and rainy days would increase about 30mm and 4.5 days respectively, with each increase of 100m in the altitude
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