西北地区降水特征分析

Analysis of Precipitation Characteristics in Northwest China

摘要: 本文利用中国地面气候资料月值数据集中西北地区111个观测站1966~2015年的逐月降水观测资料，从年际尺度对西北地区的空间分布和时间变化趋势等方面进行了分析。结果表明：西北地区降水量在空间上都呈现出从西北向东南递增的特征。西北地区年降水量呈明显增加趋势，线性趋势为0.463 mm/年。降水序列的M-K检验结果表明西北地区没有明显的突变发生，年降水量呈增加趋势。经验正交函数(EOF)分析第一特征向量结果表明西北地区整体降水东西部呈反相变化特征，1987年以后东部降水偏少而西部降水偏多。

Abstract: In this paper, the monthly precipitation observation data of 111 observation stations in northwest China from 1966 to 2015 were collected from the monthly data of surface climate data in China. The results show that precipitation in northwest China is increasing from northwest to southeast. The annual precipitation in northwest China showed an obvious increase trend, with a linear trend of 0.463 mm/year. The m-k test results of precipitation sequence showed that there was no obvious abrupt change in northwest China, and the annual precipitation showed an increasing trend. The results of EOF analysis on the first eigenvector show that the overall precipitation in northwest China is inversely correlated with that in the east and west. After 1987, the precipitation in the east is less while that in the west is more.