白龙江流域近40a气候变化及径流的响应

采用M-K突变检测法和小波分析法对白龙江流域近40a来气候变化特征进行分析。结果表明:白龙江流域气温变化20世纪80年代之前趋势不明显,80年代至90年代之间波动明显,呈下降趋势,90年代中后期气温年际变化呈显著上升趋势;降水量年际变化90年代中期之前上下波动趋势不显著,90年代中期以后呈下降趋势,流域气候趋于暖干化。上游气温年际变化存在7a、27a和4a尺度的周期变化,中下游武都和文县均以17a为主要周期;上游降水变化以7a和4a为第1、第3主周期,中下游的武都、文县则以25a、9a和4a为第1、第2和第3主周期。并且据相关分析得出降水量与径流量呈正相关关系,而气温与径流量呈负相关关系。

Spatio-temporal Climate Change and Response of Runoff in Bailong River Valley for Recent 40 Years

Based on the meteorology observation data of each site in Bailong River valley,the Mann-Kendall method and the Morlet wavelet analysis is applied to analyze the tendency characteristics of climate change of recent 40 years in Bailong River valley.The results shows that the tendency of temperature change is not obvious before 1980’s in Bailong River valley,and this trend fluctuates significantly between 1980’s and 1990’s but keeps decreasingly,while the annual change of temperature is obviously ascending after mid 1990’s;the annual precipitation trend is not significant before mid 1990’s.This demonstrates a descending trend after mid 1990’s and the climate tends to become warm and dry.The upstream area have the cycle change of 7 a,27 a and 4a,the main cycle of downstream region of Wudu and Wenxian is 17 a;the main cycle of precipitation change is 7 a and 4a in the upstream area,the downstream region of Wudu and Wenxian have 25 a,9 a and 4 a,respectively,for the first,second and third main cycle.In addition,according to the correlation analysis,there is positive correlation between precipitation and runoff,and the runoff is negatively with the temperature.