1960-2011年汉江上游降水量变化特征和区域差异

Variation and Regional Difference of Annual Precipitation in the Upper Reaches of Hanjiang River During 1960- 2011

依据1960-2011年汉江上游31个气象站数据,采用线性回归分析方法、Mann-Kendall突变检验法、空间插值法及Matlab软件小波分析法对汉江上游地区降水时空变化特征以及区域内4个典型亚区(汉中、安康、商州和十堰)间的差异进行分析。结果表明,(1)汉江上游地区的年降水量呈南多北少分布特点,且汉中最大,商州最小;各亚区间差异趋于减小。受季风气候与地貌形态等综合因素的影响,春、冬季降水量呈东南多、西北少的分布特点,夏、秋季降水量呈西南多、东北少的特点;且各区域内部也略有不同。(2)全区与各区年降水量的线性变化趋势均不显著;全区春季降水量呈显著递减趋势(P<0.05),其中商州、十堰对其贡献率最大。(3)全区和各区的年降水量突变均不显著。全区春秋季,商州、十堰春季和安康秋季降水量均发生由多到少的显著突变。(4)全区和各区的年降水量及春、秋季降水量的第一主周期均为30a左右;而局部夏、冬季降水量的周期与此不一致。汉江上游降水量的变化对南水北调中线工程正常运行有一定参考意义。

Based on meteorological data from 31 stations in the upper reaches of Hanjiang river during 1960-2011,the spatio-temporal characteristics and regional difference of 4 typical sub-areas （Hanzhong,Ankang,Shangzhou,Shiyan） was analyzed by using of linear regressive analysis,Mann-Kendall mutation test,spatial interpolation and wavelet analysis.The results showed that the spatial distribution of annual precipitation displayed a diminishing scale from south to north in the area.The maxmum value was in Hanzhong and the minimum value was in Shangzhou.The difference of annual precipitation among sub-areas decreased.It was found that the change of precipitation mainly was affected by the monsoon climate and small scale geomorphic units,and the precipitation in spring and in winter displayed a diminishing scale from southeast to northwest,the precipitation in summer and in autumn displayed a diminishing scale from southwest to northeast;but there was slightly difference in the sub-areas.The linear trend of annual precipitation was not significant in the area and sub-areas.The linear decrease trend was significant in spring （P ＜ 0.05）.Reduced precipitation of Shangzhou and Shiyan was the biggest contribution to the precipitation in spring.The mutation test of annual precipitation was not significant,and the precipitation in spring and in autumn was less mutated significantly in the area.The precipitation in Shangzhou and Shiyan was less mutated significantly in spring,and the precipitation in Ankang was less mutated significantly in autumn.The first main period of annual precipitation and precipitation in spring and in autumn was 30y in the area and sub-areas,but the period of precipitation in summer and in winter was different in the area.The change of precipitation could provide scientific reference for the normal operation of the middle route of South-North water diversion project in the area.