东北黑土区冻融循环对切沟沟壁崩塌的影响  

Effects of Freeze-thaw Cycles on Gully Wall Collapse in the Black Soil Region of Northeast China

作　　者：贾晨阳 刘宏远 于悦 马芊红 柯奇画 张科利 JIA Chenyang;LIU Hongyuan;YU Yue;MA Qianhong;KE Qihua;ZHANG Keli(State Key Laboratory of Earth Surface Processes and Resource Ecology,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京师范大学地理科学学部地表过程与资源生态国家重点实验室,北京100875

出　　处：《水土保持学报》2024年第2期109-117,325,共10页Journal of Soil and Water Conservation

基　　金：国家重点研发计划项目(2021YFD1500701)。

摘　　要：[目的]通过测量冻融循环期间沟壁崩塌体积来评价冻融循环对切沟侵蚀的贡献。[方法]2016-2018年间,选取36条切沟共计463个崩塌点开展了野外调查。基于调查结果,切沟沟壁崩塌主要表现为2种类型:块状崩塌和松散堆积。在每个崩塌点测量2种堆积体的形态参数:崩塌土壤的体积、切沟横断面的宽度和深度,以及相应沟壁土壤的剪切力和硬度。[结果](1)3年研究期间冻融作用导致的沟壁崩塌强度平均为16.12 m^(3)/(km·a)。2种崩塌类型在切沟内随机发生,单点冻融崩塌量主要集中在0~3 m ^(3),但块状崩塌导致的土方量更大。(2)切沟横断面宽度和深度是沟壁崩塌的主要影响因素,崩塌量随宽深比增大而增加,当宽深比>2.71后,崩塌量迅速增加。(3)切沟崩塌量与沟壁土壤的剪切力和硬度等紧密相关。[结论]沟壁冻融崩塌与切沟宽度和深度紧密相关,冻融崩塌量占切沟侵蚀泥沙产量的3.28%~23.68%,其影响与沟头溯源侵蚀相当。研究结果为定量评价冻融循环对切沟侵蚀贡献提供数据支撑。[Objective]To evaluate the contribution of freeze-thaw cycle(FTCs)to gully erosion by measuring the collapse volume of gully wall collapse during FTCs.[Methods]From 2016 to 2018,a total of 463 collapse points in 36 gullies were selected for field investigation.Based on the investigation results,there were two types of wall collapse:massive collapse and loose accumulation.The morphology parameters of two kinds of accumulations were measured at each collapse point,including the volume of the collapsed soil,the width and depth of the gull coross-section,and the shear force and hardness of soil of the corresponding gully wall soil.[Results](1)The average collapse strength of gully wall collapse caused by FTCs during the three-year study period is 16.12 m^(3)/(km·a).The two types of collapse occurred randomly within the gully,and the single point freeze-thaw collapse mainly concentrated in 0~3 m^(3),but the amount of soil caused by massive collapse was larger.(2)The transverse width and depth of the gully were the main factors affecting the collapse of the gully wall,and the collapse amount increased with the increase of the width-depth ratio.When the width-depth ratio>2.71,the collapse amount increased rapidly.(3)The amount of gully collapse was closely related to the shear force and hardness of the soil on the gully wall.[Conclusion]The freeze-thaw collapse of the gully wall was closely related to the width and depth of the gully cross-section,the freeze-thaw collapse accounted for 3.28%to 23.68% of the sediment yield of the gully erosion,and its influence was equivalent to that of the headward erosion of gully head.The research results provide data support for quantitatively evaluating the contribution of FTCs to gully erosion.

关 键 词：切沟沟壁崩塌 冻融循环 黑土 切沟侵蚀 

分 类 号：S157[农业科学—土壤学]