怒江流域气候特征及其变化趋势

Regional Climate and Its Change in the Nujiang River Basin

利用怒江流域及其毗邻地区16个气象台站长时序逐月气温和降水量数据,运用TFPW-MK(Trend-freePre-whiteningMann-Kendall)检验和重复迭代变化诊断等方法,分析了近几十年来怒江流域气候要素空间格局和变化特征。结果表明:(1)怒江流域气温(年平均、年最高和年最低)和年降水量由北向南总体呈递增,并与海拔相关性极为显著(α=0.01),且气候要素值随海拔升高而降低;(2)降水集中度地域差异明显,西藏境内降水集中度多达60%以上,全流域降水集中期(除贡山站外)多介于7月下旬至8月下旬;(3)流域升温趋势显著,其年平均、年最高和年最低气温变化趋势多与纬度和海拔呈显著相关,其中年平均气温增幅为0.36oC/10a;(4)部分站点气温变化存在突变点,且其多出现于暖冬频发的20世纪80年代以后;(5)年降水量总体有所增多,但变化趋势多不显著,无明显变点。

Long time series of monthly air temperature and precipitation data, which were recorded at 16 meteorological observation stations in the Nujiang River basin and its adjacent areas, were employed to analyze spatial distributions and changes of these meteorological elements in this basin during the past decades. In this research, TFPW-MK （Trend-free Pre-whitening Mann-Kendall） test and BFAST （Breaks For Additive Seasonal and Trend） were used to determine trends in climate data and to detect abrupt changes within the trend and seasonal components, respectively. The results show that air temperature and precipitation increased southward along the Nujiang River and heavily negatively correlated with altitude. The regional difference in PCD was obvious and higher PCD values, more than 60%, were observed in the Nujiang River basin in Tibet Autonomous Region. Precipitation-concentration time （PCT） in the study area （except for Gongshan） mainly from late July to late August. Generally speaking, the Nujiang River basin has become warmer in the past decades. The annual mean air temperature increases at a rate of 0.36 ℃/10a.