中国南方地区近60 a来降雨量与降雨侵蚀力时空变化研究

基于南方地区9个省份41个气象站点1956~2015年共60 a逐日降雨量资料,采用线性回归、Kriging插值等方法分析了南方地区降雨量和降雨侵蚀力的时空变化特征。结果表明:南方地区降雨以侵蚀性降雨为主,且比较集中,区域强降雨事件出现的频次在增加。南方地区年均降雨侵蚀力变化范围在3 477.30~24 878.65 MJ·mm/(hm~2·h·a)之间,平均值为9 919.93 MJ·mm/(hm~2·h·a),总体由南往北逐渐减少的分布规律。在季节分布上降雨侵蚀力主要集中在夏季。60 a来南方大部分地区年降雨侵蚀力均呈上升趋势,其中海南、浙江、江西3省上升趋势较为明显,说明这些地区面临较大的土壤侵蚀潜在压力。

SPATIOTEMPORAL VARIATION OF RAINFALL AND RAINFALL EROSIVITY IN SOUTHERN CHINA IN RECENT 60 YEARS

Daily rainfall data from 41 meteorological stations in nine provinces of southern China from 1956 to 2015 were selected for analyzing the change of rainfall and rainfall erosivity.The results showed that the trend of annual rainfall increased while the number of annual wet days decreased,and erosive rainfall was the main pattern in the area.The frequency of severe rainfall events has increased in recent 60 years.Generally,high level annual rainfall erosivity existed in the southern part of the area,while low level annual rainfall erosivity existed in the northern area.The average of annual rainfall erosivity was 9 919.93 MJ · mm/(hm2 · h · a),with the range from 3 477.30 MJ · mm/(hm2 · h · a) to 24 878.65 MJ · mm/(hm2 · h · a).The rainfall erosivity in the summer was more than those in other three seasons.The trend of annual rainfall erosivity increased in Hainan Province,Zhejiang Province and Jiangxi Province,but decreased in eastern Guangdong Province,western Guangxi Province and western Hubei Province.An increase in probability of severe soil erosion was inferred in the future.