1961-2011年渝东南地区降水变化特征分析

摘要

Based on the precipitation data from 6 weather stations in the southeast Chongqing from 1961 to 2011, the precipitation change characteristics were analyzed.The results show that the annual precipitation,spring and au-tumn precipitation are all in linear decreasing trends,especially for autumn precipitation.Summer and winter pre-cipitation is in linear increasing trends,but these trends are not significant.The cycles of annual and seasonal pre-cipitation are not same,and interdecadel cycles of summer and winter precipitation are significant.The days of an-nual rainfall,drizzle,moderate rain and heavy rain are in linear decreasing trends,especially for the last two varia-bles.There is not significant change for rainstorm days.For interdecadal change,the increasing number of rainy days mainly appears in 1990s which is mainly from the contribution of the drizzle and rainstorm days,while mod-erate rain and heavy rain days occur seldom during this period.Rainy days seldom appear in 2000 s,especially for drizzle,heavy rain and rainstorm,while moderate rain days are relatively high during this period.%利用1961-2011年渝东南地区6个气象站的降水资料，分析了该地区的气候变化特征。结果表明：1961-2011年渝东南地区年、春季和秋季降水为线性减少趋势，秋季减少趋势显著；夏季和冬季降水为线性增加趋势，但不显著。年和四季降水的周期变化不太一致，年代际周期夏季和冬季降水较显著。年雨日、小雨、中雨和大雨日数均呈线性减少趋势，中雨和大雨日数减少趋势较显著。暴雨日数整体上无明显变化。逐年代变化来看，雨日偏多最多的20世纪90年代表现为小雨和暴雨日数偏多，中雨和大雨日数偏少；雨日偏少最多的21世纪初期主要表现为小雨、大雨和暴雨日数偏少，中雨日数偏多。