1961—2019年江西省降雨侵蚀力时空变化分析

降雨侵蚀力（R）与降雨量、降雨历时、降雨强度、降雨动能有关,反映了降雨特性对土壤侵蚀的影响,是影响土壤侵蚀的重要因素之一.本文利用1961—2019年江西省25个气象站点的逐日降雨量数据,基于降雨侵蚀力模型,通过Mann-Kendall相关检验、小波分析和Kriging空间插值方法,分析江西省降雨侵蚀力空间分布及变化趋势.结果表明：江西省年均降雨量和降雨侵蚀力从赣南到赣北逐渐增加,同时降雨空间分布和降雨侵蚀力空间分布具有相似性;春季和夏季降雨侵蚀力在3 000~6 000 MJ·mm·hm^-2·h^-1·a^-1,且春季降雨侵蚀力最大值高于夏季,而秋冬季降雨侵蚀力明显小于春夏季;江西省年降雨侵蚀力平均最大值分布在赣北区域,其次为赣中,赣南最小,侵蚀力由北向南逐渐递减.研究表明江西省因降雨导致侵蚀力不断增加,尤其以春夏季更为剧烈,其空间分布存在明显差异.

Spatial-temporal variation of rainfall erosivity in Jiangxi province from 1961 to 2019

As one of the important factors affecting soil erosion, rainfall erosivity (R) is related to rainfall characteristics of amount, duration, intensity, and kinetic energy.Using the daily rainfall data of 25 meteorological stations in Jiangxi province from 1961 to 2019, we analyzed the spatial distribution and variation trends of rainfall erosivity in Jiangxi province via rainfall erosivity model, as well as Mann-Kendall correlation test, wavelet analysis and Kriging spatial interpolation.The results showed that the annual average rainfall and rainfall erosivity varied similarly in spatial distribution, which were gradually increased from southern Jiangxi to northern Jiangxi;the rainfall erosivity in spring and summer ranged from 3 000 to 6 000 MJ·mm·hm^-2·h^-1·a^-1, which was significantly higher than that in autumn and winter, with the maximum rainfall erosivity occurring in spring;the average annual rainfall erosivity in Jiangxi decreased from north to south, which maximized in northern Jiangxi and followed by central Jiangxi then southern Jiangxi.The research shows that the rainfall-induced soil erosion was increasing in Jiangxi province, especially in spring and summer, and there were obvious differences in their spatial distribution.