1961-2016年四川地区不同量级不同持续时间降水的时空特征分析

利用四川地区122站逐日降水数据，采用均值、气候趋势系数等统计方法，对1961-2016年不同量级不同持续时间降水的空间和时间变化特征进行了分析，结果表明：盆地和攀西地区小雨、中雨、大雨和总暴雨所占年降水量比例接近，高原地区小雨降水量约占50%以上，中雨约40%，大雨约10%；整个四川地区小雨日数占总降水日数75%以上，量级越高降水日数越少。年降水量在盆地和攀西地区为减少趋势，高原则相反，年降水日数除了在高原局部微弱增加外其他地区皆减少且大部分区域减少趋势通过99%的显著性水平检验，这种趋势显著性主要体现在小雨量级降水。随着降水量级的增加，高原、盆地东北、攀西和盆地东南的部分地区出现了降水量和降水次数增加趋势，这可能说明高原地区年降水量的增加由小雨量级降水效率以及中雨和大雨降水次数增加导致，盆地和攀西部分地区年降水量的增加主要由降水量级大的降水次数增加导致。

Temporal and spatial characteristics of different classes and various durations of precipitation in Sichuan Province from 1961 to 2016

Based on the daily precipitation data from 122 stations in Sichuan Province, the spatial and temporal variations of different classes and duration rainfall from 1961 to 2016 are analyzed by using various statistics methods, such as mean, climate trend coefficient and so on. The results show that the proportion of light rain, moderate rain, heavy rain and all kinds of rainstorm was similar to each other in the basin and Panxi area. But in plateau region, the light rain accounts for more than 50% of the amount of precipitation, and the moderate rain for 40%, heavy rain for 10%. In the whole Sichuan Province the days of light rain account for more than 75% of the total rainy days, and the proportion was decreased as the magnitude increase. The annual precipitation mainly had decreased in the basin and Panxi, increased in plateau region. While the annual rainy days had decreased in any other regions except the fraction of the plateau, and in the main region they had passed the 99% significant level test. The characteristic trend of annual rainy days was mainly reflected in the light rain. As the magnitude of rainfall increasing, the amount and days of precipitation in the plateau, Panxi, northeast and southeast of the basin showed an increase trend, which may indicate that the increase of annual precipitation in the plateau was caused by the precipitation efficiency of the light rain and the increasing times of moderate and heavy rain, the increase of the annual precipitation in part of the basin and Panxi area was mainly caused by the increasing times of the large magnitude rainfall.