砒砂岩泻溜侵蚀的坡向分异及其与气象因素的响应  

Slope Aspect Differentiation of Pisha Sandstone Slide Erosion and Its Response to Meteorological Factors

作　　者：任亚楠 李龙 张尚轩 张宇 周星辰 REN Yanan;LI Long;ZHANG Shangxuan;ZHANG Yu;ZHOU Xingchen(College of Desert Management,Inner Mongolia Agricultural University,Hohhot 010018,China;Key Laboratory of Desert Ecosystem Protection and Restoration,State Forestry Administration,Hohhot 010000,China)

机构地区：[1]内蒙古农业大学沙漠治理学院,呼和浩特010018 [2]国家林业局荒漠生态系统保护与修复重点实验室,呼和浩特010000

出　　处：《水土保持学报》2024年第6期44-53,共10页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(42267049)。

摘　　要：[目的]泻溜作为砒砂岩区典型的重力侵蚀方式,已成为沟道内重要的粗砂物质来源,严重威胁流域生态安全,明确该地区侵蚀机理对黄河流域生态保护和高质量发展战略具有重要意义。[方法]以内蒙古砒砂岩沟坡系统为研究对象,基于野外定位监测,利用三维激光扫描技术,分析不同坡向下沟坡侵蚀界面微地形变化与侵蚀特征的时空变化规律及其与气象要素之间的响应关系。[结果](1)砒砂岩沟坡存在明显的泻溜侵蚀现象,且坡向分异较为明显。其中,阴坡平均侵蚀面积占研究区总面积的43.11%,阳坡平均侵蚀面积占研究区总面积的45.48%。阳坡的侵蚀强度大于阴坡,且地表粗糙度的变化幅度在阳坡更为明显。阴坡地表起伏度、地表切割度和高程变异系数的变化规律更具显著性,坡向是影响沟坡重力侵蚀的关键地形因素。(2)沟坡后退速率与地表起伏度和地表切割度之间呈极显著正相关(p<0.01)。阴坡沟坡后退速率与微地形因子的拟合度优于阳坡,R^(2)分别为0.721和0.631,不同坡向微地形因子与沟坡后退速率的拟合度优于侵蚀面积与侵蚀量。(3)在砒砂岩区7—8月期间,影响阴坡侵蚀的气象因子重要性依次为气温>降雨量>太阳辐射>相对湿度>风速,阳坡则表现为气温>相对湿度>风速>降雨量>太阳辐射。GAM模型对侵蚀特征的坡向变异具有较好的解释能力。[结论]研究结果可为砒砂岩区重力侵蚀机理研究和生态建设提供理论参考。[Objective]As a typical mode of gravity erosion in the Pisha sandstone area,debris sliding has become a significant source of coarse sand material within gullies,seriously threatening the ecological security of the basin.Clarifying the erosion mechanisms in this region is of great importance for the ecological protection and high-quality development strategy of the Yellow River Basin.[Methods]Using the gully slope system in Inner Mongolia as the study area,field monitoring and three-dimensional laser scanning technology were employed to analyze the spatial and temporal changes in micro-topography and erosion characteristics of the erosion interface under different slope aspects.Additionally,the relationships between these changes and meteorological factors were investigated.[Results](1)The Pisha sandstone gully slopes exhibited significant debris sliding erosion,with distinct slope aspect differentiation.The average erosion areas of the shady slope and the sunny slope accounted for 43.11%and 45.48%of the total study area,respectively.The erosion intensity on the sunny slope was greater than that on the shady slope,with the variation in surface roughness being more pronounced on the sunny slope.However,the variations in surface relief,surface dissection and elevation variation coefficient were more significant on the shady slope.Slope aspect was a critical topographic factor influencing gravity erosion on gully slopes.(2)There was a highly significant positive correlation(p<0.01)between the retreat rate of gully slopes and surface relief and surface dissection.The correlation between the retreat rate of gully slopes and micro-topographic factors was better for shady slopes(R^(2)=0.721)compared to sunny slopes(R^(2)=0.631).The fitting effect of micro-topographic factors with gully slope retreat rate was superior to that with erosion area and erosion volume.(3)During the period from July to August in the Pisha sandstone area,the importance of meteorological factors affecting the erosion of the shaded slope was tempe

关 键 词：泻溜 砒砂岩区 沟坡系统 坡向 

分 类 号：S157.1[农业科学—土壤学]