Arid Zone Research ›› 2024, Vol. 41 ›› Issue (5): 797-811.doi: 10.13866/j.azr.2024.05.08

• Land and Water Resources • Previous Articles     Next Articles

The physicochemical and strength characteristics of root-soil composite system in the Xiazangtan super large scale landslide area of the upper Yellow River

FAN Qiuxuan1(), YANG Fucheng1, FU Jiangtao2, LIU Changyi1, HU Xiasong1(), XING Guangyan3, ZHAO Jimei3, ZHANG Peihao1   

  1. 1. School of Geological Engineering, Qinghai University, Xining 810016, Qinghai, China
    2. Academy of Agriculture and Forestry Sciences, Qinghai University, Xining 810016, Qinghai, China
    3. College of Agriculture and Animal Husbandry, Qinghai University, Xining 810016, Qinghai, China
  • Received:2023-10-26 Revised:2024-02-04 Online:2024-05-15 Published:2024-05-29

Abstract:

For this study of the physical and chemical properties and mechanical characteristics of soil in the distribution area of Xiazangtan super large scale landslide of the upper Yellow River, plants and soil samples at different positions of the landslide were collected, and the plant growth index, soil density, water content, root content, 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 increase 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 altitude, 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 matter, 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.

Key words: the upper Yellow River, Xiazangtan landslide, the physical and chemical properties of soil, root-soil composite system, shear strength