【摘要】 选用长江上游流域1961—2022年1 km空间分辨率的月尺度格点降水数据，基于创新趋势分析法、MannKendall检验法等方法对长江上游流域四季和全年各量级降水量的时空特征进行分析，并使用交叉小波分析探究流域年降水量的驱动因素。结果表明：1)1961—2022年长江上游流域的年降水量整体呈微弱增加趋势，春季、夏季和冬季降水呈现增长趋势，其中强降水等级增幅接近或超过10%，而秋季降水在全部降水等级均呈减少趋势；2）流域年降水量和季节降水整体均呈东多西少的分布格局，夏季降水空间分布与年降水分布最为接近，全年来看，降水量变化趋势整体呈由东南减少变为西北增加；3）长江上游流域的年降水量与大气环流异常因子和太阳活动密切相关，其中，厄尔尼诺-南方涛动（El Ni?o-southern oscillation, ENSO），北极涛动（Arctic oscillation, AO），太平洋年代际振荡（Pacific decadal oscillation, PDO）和太阳黑子指数均与年降水量存在较为显著的周期相关性。更多还原

【Abstract】 Based on the monthly grid precipitation data with a spatial resolution of 1 km in the Upper Yangtze River Basin from 1961 to 2022, the spatial-temporal characteristics of precipitation at various magnitudes in four seasons and throughout the year in the Upper Yangtze River Basin is analyzed by using methods such as the innovation trend analysis(ITA) and the Mann-Kendall test, and the driving factors of the annual precipitation in this basin are explored by using cross-wavelet analysis method. The results indicate that: 1) The annual precipitation in the Upper Yangtze River Basin from 1961 to 2022 exhibites a slight increasing trend. Precipitation in spring, summer, and winter shows an increasing trend, and shows a trend of close to or exceeding a 10% increase in the heavy precipitation grade. The precipitation in autumn exhibits a decreasing trend in all precipitation grades; 2) The annual precipitation and seasonal precipitation in the basin as a whole shows a distribution pattern of more in the east and less in the west, and the spatial distribution of summer precipitation is closest to that of annual precipitation. From an annual perspective, the trend of precipitation shows a general change from a decrease in the southeast to an increase in the northwest; 3) The annual precipitation in the Upper Yangtze River Basin is closely related to the anomalous factors of the atmospheric circulation and solar activity. Among them, El Ni?o-southern oscillation(ENSO), Arctic oscillation(AO), Pacific decadal oscillation(PDO) and the sunspots index all exhibit a relatively significant periodic correlation with the annual precipitation.更多还原