60年来渭河关中地区气温与降水变化及其原因

基于渭河关中地区1951年-2013年气温和降水资料,运用线性回归、Mann-Kendall检验、集中度和集中期等方法分析了60年来气温和降水的变化趋势、突变特征,并探讨了变化原因。结果表明:(1)渭河关中地区平均气温呈显著上升趋势,增幅为0.206℃/(10a),冬季对流域平均气温的变暖贡献最大。全年及各季平均气温的突变时间均为20世纪90年代中期。(2)降水呈不显著减少趋势,每年约减少0.5775 mm,春季和秋季对下降趋势贡献较大。降水量突变点较为复杂,在许多年份都有不同程度的突变。降水年内分配较为稳定,集中度基本维持在0.5~0.6,集中期为7月。(3)渭河关中地区气温、降水变化的原因有自然因素和人为因素。自然因素主要有太阳活动、大气环流、季风影响,人为因素主要是温室气体排放以及土地覆被类型改变。

Variation and reason analysis of temperature and precipitation of Weihe River in Guanzhong area in the last 60 years

The identification of changes and reasons for hydrological factors has practical significance for resource utilization and the ecological health of river basin .Based on the data from 1951-2013 of Weihe River in Guanzhong area ,the trend and muta‐tion of temperature and precipitation were analyzed with linear regression ,Mann‐Kendall test ,concentration degree and concen‐tration time .The change reasons of temperature and precipitation were elaborated .The results were as follows :(1) The annual average temperature showed a significant increasing trend ,with 0 .206 ℃ /(10a) ,and winter contributed most .Obvious muta‐tions occurred in the mid‐1990s for the annual and seasonal mean temperature .(2) The annual precipitation showed an insignifi‐cant decrease of about 0 .5775 mm per year .Spring and autumn contributed greatly to the downward trend .The mutations were complicated ,with varying degrees in each era .The distribution of precipitation was stable ,with concentration degree and concen‐tration time remaining at 0 .5~0 .6 and in July ,respectively .(3) The changes of temperature and precipitation were mainly the combined results of natural factors and human factors .Natural factors included solar activity ,atmospheric circulation and mon‐soon impact ,and the human factors were mainly greenhouse gas emissions and land cover changes .