黄河上游夏藏滩巨型滑坡区根-土复合体理化与强度特性OA北大核心CSTPCD

For this study of the physical and chemical properties and mechanical characteristics of soil in the dis-tribution area of Xiazangtan super large scale landslide of the upper Yellow River,plants and soil samples at dif-ferent positions of the landslide were collected,and the plant growth index,soil density,water content,root con-tent,shear strength index,and nutrient element content were measured.Spearman's correlation analysis was used to explore the vegetation types,physical and chemical properties of soil,and the shear strength characteristics of the root-soil composite system in different positions of the landslide.The number of plant species tended to in-crease as the altitude decreased,and the dominant herbaceous herbs were Stipa aliena,Oxytropis ochrocephala,and Artemisia desertorum.The pH of the soil in the distribution area of the landslide was neutral to alkaline.The contents of organic matter,total nitrogen,and total phosphorus change greatly at the trailing edge of the landslide,whereas the contents of total potassium,alkali-hydrolyzed nitrogen,and four other nutrients change greatly but do not show obvious variation.The water content of soil first increases and then decreases with the decrease in al-titude,while the density of soil increases as the altitude decreases,increasing by 7.05%and 5.88%,respectively.The cohesion c value and root content of the root-soil composite system first increased and then decreased as the altitude decreased.In addition,Spearman correlation analysis showed that the cohesion c value of the root-soil composite system was negatively correlated with altitude,but positively correlated with root content,organic mat-ter,and water content.The results of this study have practical significance for guiding the prevention and control of geological disasters such as soil erosion,and shallow landslide in the upper reaches of the Yellow River,from Longyang Gorge to Jishi Gorge.