1961-2015年四川省汛期极端降水指数时空变化研究

利用近55a四川省156个气象台站的的汛期（月）逐日降水量资料，采用F检验、滑动t检验、小波分析等方法对近55a四川省汛期极端降水指数的时空特征、周期特征进行了分析.结果表明：1）近55a四川省汛期降水总量、强降水量、降水百分率、连续5日最大降水量及暴雨日数均在绝大部分地区呈增加趋势，在川中部地区呈减少趋势；降水强度及1日最大降水量在四川省大部分地区呈增加趋势.2）在年代际变化率上，汛期强降水、降水强度、降水百分率、1日最大降水量、连续5日最大降水量及暴雨日数均对汛期总降水量的长期气候变化趋势具有一定的指示意义.3）降水总量、强降水及降水强度、日最大降水量、暴雨日数均存在准8a以及3~4a的短周期；降水百分率以及连续5日最大降水量为6~8a和3~4a的短周期.

Spatial-Temporal Variation of Extreme Precipitation Indices During the Main Flood Season in 1961-2015 in Sichuan

Based on the daily precipitation data in June-Aug. of 156 meteorological stations in Sichuan during 1961-2015, F test, moving t-test, wavelet analysis and low pass filtering (LPF) are used to analyze the temporal and spatial distributions of extreme precipitation indices in Sichuan in the recent 55 years. The conclusions are as follows. 1) Spatially, total precipitation amount, heavy precipitation amount, precipitation abnormity percentage, maximum precipitation in five consecutive days and heavy rain days in the flood season during 1961-2015 in Sichuan showed a rising trend in the western and eastern parts of the province and a declining trend in the middle part, and precipitation intensity and day maximum precipitation showed an ascending trend in most parts of the province. 2) On the decadal variability, heavy precipitation amount, precipitation intensity, precipitation abnormity percentage, day maximum precipitation, maximum precipitation in five consecutive days and heavy rain days are of certain significant instruction of the total precipitation during the main flood season. 3) There are 8-year and 3-4-year periodic oscillation of total precipitation, heavy precipitation amount, precipitation intensity, day maximum precipitation and heavy rain days during the 55 years, and there exist 6-8-year and 3-4-year periodic oscillation of precipitation abnormity percentage and maximum precipitation in five consecutive days during the all time series.