孟定盆地54年来气温降水变化特征分析

Analysis of the Variation Characteristics of the Temperature and Rainfall in Mengding Basin over Recent 54 Years

基于孟定站1955～2008年气温、降水量观测数据,应用回归分析法、方差分析法和M-K检验法等方法,分析了在全球气候变暖背景下孟定盆地气温、降水的时空变化特征以及变化趋势、年代际变化及突变特征.结果表明,54年来孟定气温升高了1.5℃,升高趋势显著,20世纪90年代后期以来增暖趋势特别明显;从季节来看,以冬季增暖贡献最大;年和各季均温均通过99.9％的信度检验.54年来降水量减少了103.68 mm,减少趋势显著,21世纪以来减少趋势最显著;从季节来看,春季降水有增多的趋势,夏、秋、冬季均呈减少趋势,尤以夏季减少最明显;夏、秋两季降水量通过99.9％的信度检验,年和其余各季降水量未通过信度检验;气温变化周期不明显,降水存在明显的变化周期;年和各季均温及降水量均存在一个或多个突变点,20世纪90年代以来气温突变增加趋势显著,年和各季均超过0.01信度的临界线;春季降水量在70年代以来突变增加显著,年和其余各季降水量在80年代中期以来突变减少.

Based on the temperature and rainfall data from 1955 to 2008 in Mengding Basin, the spatial-temporal variation characteristics, vari- ation trend, annual change and mutation characteristics of temperature and precipitation were analyzed under the background of global warming by using regression analysis, variance analysis and M-K test method. The results showed that： climate warming trend was obvious over recent 54 years, the annual average temperatures rising by 1.5 ℃. Warming trend wasparticularly significant since the late 1990s and the largest contribu- tion to heating was made in winter. Both the annual average temperature and seasonal mean temperature passed 99.9% reliability test. Precipita- tion decrease trend was obvious in past four years and since 2000 it was the most remarkable. The annual precipitation decreased by 103.68 mm. Precipitation＇tend to increase in spring but tend to decrease in summer, autumn and winter among which it decreased most obviously in summer. Precipitation in summer and autumn was above 99.9% reliability test but the annual average temperature and seasonal mean temperature were un- der the reliability test. Annual and seasonal mean temperature and rainfall had one or more mutation points. It was obvious that temperature mu- tation tend to increase since the 1990s. Annual and seasonal mean temperature was more than 0. O1 critical path. The rainfall mutation in spring increased significantly since the 1970s. Annual and seasonal mean rainfall mutation began to decrease since mid 1980s.