• 论文 •

### 西北各省季节降水变化及其贡献的差异分析

1. 中国农业大学资源与环境学院，北京 100193
• 出版日期:2019-08-20 发布日期:2019-08-01
• 作者简介:孙悦（1995?），女，硕士生，主要从事全球环境变化研究。E-mail：sunyue.joy.nana@gmail.com
• 基金资助:

“十三五”国家重点研发计划（项目编号2017YFC1502801）

### Seasonal Variation about the Occurrence Frequency of Different Types of Precipitation and Their Relative Contribution over Northwest China

SUN Yue，GAO Ji-qing，YANG Xiao-guang

1. College of Resources and Environmental Sciences, China Agriculture University, 100193 Beijing, China
• Online:2019-08-20 Published:2019-08-01

Abstract:

Based on the long-term daily precipitation data measured at 124 meteorological station in Northwest China from 1951 to 2015, the difference of the contribution rate of precipitation amount and precipitation days among different precipitation grades in each season were investigated and the variation characteristics of spatial and temporal were clarified in this study. How the changes of precipitation amount (days) in different seasons affect annual precipitation amount (days) and how the changes of precipitation amount (days) in different grades affect seasonal precipitation amount (days) were also figured out. The results showed that: (1) annual precipitation days decreased significantly with an averaging downward trend of 0.1 days per decade in Northwest China from 1951 to 2015. Significant difference was shown in both precipitation days and its temporal variation among different observation stations. (2) The annual precipitation amount in Northwest China also increased significantly from 1951 to 2015, with an average increasing trend of 3.9mm per decade. (3) Strong seasonal variations were shown in precipitation amount and days, with the most in summer and the least in winter. The contribution rate of summer precipitation amount and days in each province was 50%-63% and 35%-48%. The precipitation amount was similar in spring and autumn. In each season, the light and moderate rain was mainly, which accumulative contribution rate of precipitation days was above 90%. The rainstorm only occurred in summer, which contribution rate was less than 1%. (4) The variation of precipitation amount(days) in summer and autumn was the most important reason for the change of annual precipitation amount(days), and the change of light and moderate rain was the most important reason for the change of total seasonal precipitation amount(days). The precipitation in spring and winter was not dominant in the annual precipitation, and the heavy and rainstorm were not dominant in the current season (annual) precipitation, so their effect were not obvious.