日喀则地区近45年降水时空特征分析

Analysis of Spatial and Temporal Characteristics of Precipitation in Shigatse Area in Recent 45 Years

摘要: 本文基于日喀则地区7个气象站1979~2023年共计45年逐年降水资料，利用线性倾向估计和累计距平方法、经验正交函数法、小波分析法对日喀则地区降水进行时空变化特征分析，结果表明：日喀则地区各区域降水空间变化特征呈东南部多、东部及西部降水偏少特点，降水量分布与地形显著相关，降水主要集中在日喀则东南部地区，地形因素对降水有调制作用。降水呈现波动的特征，年降水量呈现以2000年为界的年代际变化，且增加趋势不明显，日喀则年降水量存在两个显著的周期，分别为2~3年、5年，小波方差与第一主成分的波动周期大致一致。

Abstract: This article is based on annual precipitation data from 7 meteorological stations in the Shigatse region for 45 years from 1979 to 2023. Linear tendency estimation and cumulative anomaly methods, empirical orthogonal function method, and wavelet analysis are used to analyze the spatiotemporal variation characteristics of precipitation in the Shigatse region. The results show that the spatial variation characteristics of precipitation in each region of the Shigatse region are characterized by more in the southeast and less in the east and west, and the distribution of precipitation is significantly correlated with terrain. Precipitation is mainly concentrated in the southeastern region of Shigatse, and terrain factors have a modulating effect on precipitation. The precipitation exhibits fluctuating characteristics, with an interdecadal variation of annual precipitation bounded by the year 2000, and the increasing trend is not obvious. There are two significant periods of annual precipitation in Shigatse, which are 2~3 years and 5 years, respectively. The wavelet variance is roughly consistent with the fluctuation period of the first principal component.