近56a武汉市降水气候变化特征分析

以武汉市1951—2006年逐日降水资料为基础，采用累积距平、线性趋势、移动T检验、5％分位数、小波分析等方法，分析了近56a来武汉市降水气候变化特征。结果表明：（1）近56年来，武汉市年降水量、降水强度呈增加趋势，而降水日数呈减少趋势；（2）除春季外，其它季节以及汛期、梅雨期、伏旱期等时段的降水量均有所增加；降水日数在春、秋季、汛期呈下降趋势，其余时段则为增加趋势；降水强度在夏季、伏早期呈减小趋势，其余时段均为增大趋势；（3）梅雨期、年的降水量变化较为一致，其周期性变化明显，主要表现为10a年代际周期，突变点约在1979年；（4）1960、1970年代暴雨日数较少，在1979年前后突变增多后，进人多暴雨阶段；（5）历年最大日降水量、5％分位数极端降水强度、暴雨平均强度变化略有减少趋势但不显著，而大暴雨平均强度减弱趋势明显。

Analysis on the Change Characteristics of Precipitation in the Latest 56 Years in Wuhan

Based on the data of daily rainfall from 1951 to 2006 in Wuhan, several methods such as linear tendency, cumulative distance, analysis of little wave and Moving-T-Test （M33） are adopted to analyze the rainfall climate change. The results show： （1） in the latest 56 years in Wuhan, the rainfall and rain intensity are increasing and the number of raining day is decreasing; （2） except the spring, the rainfall in the flood season, and hot-drought season is increasing; the number of raining day is decreasing in spring, autumn and the flood season and increasing in the other spells; the rain intensity is decreasing in summer especially the hot-drought season; （3） there are increasing trend of the rainfall and the number of raining day both in the flood season and the total year with a obvious period of ten years; （4） there is a abrupt increasing change for the number of heavy rain day near 1979 with the less number of heavy rain day in 1960s and 1970s and more in 1980s and 2000s; （5） all indexes of the extreme precipitation including the yearly maximum rainfall, 5% value of daily rainfall, the number of raining day and the average rain intensity show a little decreasing tendency, but the average intensity of the torrential rain （daily rainfall ≥ 100 mm） is decreasing obviously.