基于湿润指数的吉林省 1961 2017 年地表干湿时空变化特征分析

Analysis of Spatio-temporal Changes of Surface Dry-wet Condition in Jilin Province from 1961 to 2017 Based on Humidity Index

利用吉林省46个气象站点19612017年观测资料,采用湿润指数、变化趋势、累计距平、IDW插值等方法,分析了研究区57年来地表干湿状况时空变化特征及空间差异。结果表明:(1)19612017年,吉林省具有不显著的年际变湿发展趋势,在1984年、1994年分别向变湿和变干趋势转变;在季节变化上,相对干旱的春、冬季均有明显变湿趋势,而湿润的夏、秋季则有变干的趋势。(2)21世纪10年代、20世纪80年代最为湿润,干湿区的分界线整体向西、向北移动,湿润和半湿润范围扩大。(3)吉林省地表湿润指数呈现出东高西低、东南高西北低的分布特点,大部分地区湿润指数变化趋势为正,以变湿趋势为主导;吉林省半干旱区的南部和湿润区的南部变干趋势明显。(4)湿润指数的变异系数呈现由东向西递增的分布特征,吉林省西部半干旱地区比半湿润、湿润地区的变异系数更大。

The surface humidity index is calculated using the observation data of 46 meteorological stations in Jilin province from 1961 to 2017.Based on this index,we analyze the spatial and temporal variation characteristics of the surface dry-wet condition in the study area in the past 57 years,using the variation trend,climatic tendency rate,moving t-test,M-K test,IDW interpolation and other methods.The results show as follows.(1)From 1961 to 2017,Jilin experienced a non-significant trend of inter-annual humidification development.There were abrupt humidification and drying points respectively in 1984 and 1994 at the inter-annual scale.In terms of seasonal changes,relatively dry spring and winter had a significant trend of wetting,while wet summer and autumn had a trend of drying in the past 57 years.(2)In the 2010s and the 1980s,it was the wettest.The dividing line of the humid and arid zones moved to the west and north as a whole,and the range of humid and semi-humid zones expanded.(3)The spatial distribution of the multi-year average surface humidity index in Jilin was generally characterized by east high,west low,southeast high and northwest low.The variation trend of humidity index was positive in most regions,and the trend of humidification was dominant.In the south of semi-arid and humid zones,the drying trend was obvious.(4)The variation coefficient of humidity index shows the distribution characteristic of increasing from east to west.The variation coefficient in semi-arid zones in western Jilin is greater than that in semi-humid and humid zones.