黄河兰州上游地区降水、气温变化及趋势诊断

Variation and Trends Detection of Precipitation and Temperature in the Upper Reaches of Yellow River

基于黄河上游38个站点近50年的资料,分析了降水、气温的时空变化特征,采用线性回归法和非参数Mann-Kendall方法,检验了兰州上游各子区间降水和典型站点气温的变化趋势。结果表明:1)20世纪90年代以来,兰州以上各区间降水量均少于多年均值,呈现出减少趋势,其中洮河流域最显著,其平均递减率为19.9mm/10a;2)各代表站年均气温呈显著上升趋势,平均升幅在0.09~0.374℃/10a之间;3)就季节而言,冬季升温最明显,其次为秋季,其平均递升率分别为0.199~0.763℃/10a和0.067~0.338℃/10a。

Based on the precipitation and temperature at 38 stations in the Upper reaches of Yellow River,spatial and temporal characteristics of precipitation and temperature in the recent 50 years from 1955 were analyzed.Variation trends of precipitation over the sub-areas and temperature at representative stations were detected with linear regression method and Mann-Kendall rank correlation method.The results indicated that annual precipitation over the four sub-areas presented weak decreasing trend except that in ...