裸露砒砂岩区降雨条件下坡面微地形变化规律  

Change Law of Slope Micro-topography Under Rainfall Condition in Exposed Feldspathic Sandstone Region

作　　者：杨振奇 郭建英[1] 秦富仓 田秀民[1] 刘艳萍[1] YANG Zhenqi;GUO Jianying;QIN Fucang;TIAN Xiumin;LIU Yanping(Institute of Water Resources for Pastoral Area,Ministry of Water Resources of China,Hohhot 010020;Desert Science and Engineering College,Inner Mongolia Agricultu-ral University,Hohhot 010018)

机构地区：[1]水利部牧区水利科学研究所,呼和浩特010020 [2]内蒙古农业大学沙漠治理学院,呼和浩特010019

出　　处：《水土保持学报》2021年第3期111-118,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41967008);内蒙古科技计划项目(20200GG0126)。

摘　　要：裸露砒砂岩区是黄河粗泥沙集中来源区之一,研究裸露砒砂岩区降雨条件下坡面微地形变化规律,对于科学指导植被建设、减轻入黄泥沙有重要意义。以裸露砒砂岩区鲍家沟小流域为研究对象,运用系统聚类和线性回归相结合的方法,划分裸露砒砂岩区降雨类型,研究降雨类型对裸露坡面产流产沙的影响,分析降雨条件下坡面微地形变化规律。结果表明:(1)裸露砒砂岩的自然降雨可以分为4种类型,第1类降雨为长历时暴雨,第2类降雨为长历时的中到大雨,第3类降雨为短历时暴雨,第4类降雨为短历时的小到中雨。(2)第2类降雨的P与土壤流失量间呈良好的抛物线函数关系,I_(30)与径流深间存在多项式函数关系;第3类降雨的P与径流深和土壤流失量间存在多项式函数关系;第4类降雨的I_(30)与水流含沙量间有一定的函数关系。(3)在1个雨季内,裸露基岩坡面微地形坡度的平均值由22.76°增长至23.09°,坡面细沟的细沟密度由0增加至33.73 m/m^(2),随着坡面微地形持续向利于侵蚀发生的方向发展,坡面产流产沙量随之增加。The exposed feldspathic sandstone region is one of the main source regions of coarse sandiment in the middle reach of Yellow River.Studying the change law of slope micro-topography under rainfall condition had great significance to guide vegetation construction and reduce coarse sandiment into Yellow River.In this study,taking Baojiagou watershed in feldspathic sandstone region as the research object,through hierarchical clustering method and linear regression method,we divided the types of rainfall and studied their effects on runoff and sediment yield,we also analyzed the change law of slope micro-topography under rainfall condition.The results showed that:(1)The natural rainfall in the research area could be divided into four types,the typeⅠwas long-duration heavy rain,the typeⅡwas long-duration moderate to heavy rain,the type typeⅢwas short-duration heavy rain,and the type IV was short-duration light to moderate rain.(2)Parabolic function correlation were existed between the P of the typeⅡrainfall and soil loss amount.There was a polynomial function relationship between I_(30)of the typeⅡrainfall and runoff depth.Polynomial function correlation were existed between the P of the typeⅢrainfall and runoff depth and soil loss amount.There was a certain functional relationship between the I_(30)of the typeⅣrainfall and the sand content in the water flux.(3)During one rainstorm season,the average value of micro-topography slope grandiant of exposed bed rock slope increased from 22.76°to 23.09°,the rill density on the slope surface increased from 0 to 33.73 m/m^(2).With the continuous development of microtopography of slope surface,which was beneficial to the occurrence of erosion,the runoff and sediment yield on the slope surface increased.

关 键 词：裸露砒砂岩区 降雨特征 土壤侵蚀 坡面微地形 

分 类 号：S157.1[农业科学—土壤学]