太行山脉不同量级降雨侵蚀力时空变化特征

Spatial and temporal variations of rainfall erosivity at each level in Taihang Mountain

基于太行山脉及其周边地区76个气象监测站点1954-2016年逐日降雨数据,建立了基于不同量级侵蚀性年降雨量模拟年降雨侵蚀力的简易模型,并采用气候倾向率、小波周期分析、重心模型、Co-Kriging插值、Mann-kendall非参数趋势检验以及突变分析等方法,分析了不同量级降雨侵蚀力时空变化特征及其影响因素。结果表明:(1)太行山脉地区年降雨侵蚀力简易模型为y=0.182x11.095+5.463x20.982+9.401x31.017+15.258x4-26.753,且多年降雨侵蚀力呈小幅上升趋势,10年间上升了2.4 MJ·mm·hm-2·h-1·a-1,同时存在约20年的主周期和6年的小周期变化,并在1996年发生显著突变;中雨和大雨侵蚀力63年间均呈上升趋势,而暴雨和特大降雨侵蚀力呈下降趋势;春秋两季主要受中雨和大雨侵蚀力的影响,而夏季则主要受特大降雨侵蚀力的影响。(2)太行山脉地区各量级降雨侵蚀力最大值主要分布于太行山脉东南部以及五台山地区,最小值主要分布于地区的东北部;运用重心模型发现各量级降雨侵蚀力重心在春夏季节整体向东部以及东北部地区进行迁移,而秋冬季节则向南部以及西南地区迁移,形成一个循环,且与冬夏季风的控制时间相符。(3)太行山脉地区不同量级降雨侵蚀力与侵蚀性降雨量均呈显著正相关(P<0.01),大雨和特大降雨侵蚀力分别与纬度、海拔呈显著负相关(P<0.05),这主要与副热带高压移动、地形、海拔以及自然地理环境等因素有关。

This paper is mainly based on daily rainfall data from 76 meteorological monitoring stations in the Taihang Mountains and its surrounding areas from 1954 to 2016.A simple model is established to simulate the annual rainfall erosivity based on different magnitudes of aggressive annual rainfall.The climatic trend rate,wavelet period analysis,center of gravity model,Co-Kriging interpolation,Mann-Kendall non-parametric trend test and mutation analysis were used to analyze the spatial and temporal variations of rainfall erosivity and their influencing factors.The results show that:(1)The simple model of annual rainfall erosivity in the Taihang Mountains area is y=0.182 x11.095+5.463 x20.982+9.401 x31.017+15.258 x4-26.753,and the erosivity of rainfall over years showed a slight upward trend,and it increased by 2.4 MJ·mm·hm-2·h-1·a-1 in 10 years.There is also a major cycle of about 20 a and a small cycle of 6 a,and significant mutations occurred in 1996.The eclipse of moderate rain and heavy rain showed an upward trend in 63 years,while the violent rain and extraordinary rainfall erosivity showed a downward trend.The spring and autumn seasons are mainly affected by moderate and heavy rain erosivity,while summer is mainly affected by excessive rainfall erosivity.(2)The maximum rainfall erosivity of all magnitudes is mainly distributed in the southeastern part of the Taihang Mountains and the Wutai Mountain areas.The minimum is mainly distributed in the northeastern part of the study area.Using the center of gravity model,we found that the gravity center of each magnitude of rainfall migrating migrates to the east and northeast in spring and summer,while that of the autumn and winter seasons migrates to the south and southwest,forming a cycle that is consistent with the control time of the winter and summer monsoons.(3)There was a significant positive correlation between rainfall erosivity and erosive rainfall in different magnitudes in the Taihang Mountains(P<0.01).Heavy rain and extraordinarily heavy rainfall erosivity were significantly negatively correlated with latitude and altitude(P<0.05).This is mainly related to factors such as subtropical high pressure movement,topography,elevation and natural geographical environment.