Subjects: Geosciences >> Geography submitted time 2024-06-12 Cooperative journals: 《干旱区研究》
Abstract： There are a large number of rodent mounds in the alpine grassland rodent activity area of the Yellow River source, and soil wind erosion is easy to occur under the influence of dry and windy climate. In order to clarify the characteristics and laws of soil wind erosion in rodent mounds, this study took the Ochotona curzoniae and Myospalax baileyi mounds in 14 test areas at different altitudes and vegetation coverage in the Yellow River source basin as the research objects. The field simulated wind erosion test device was used to analyze and discuss the soil loss and nutrient loss law of rodent mounds in different regions under different wind speeds. results showed: (1)There was a significant difference in the amount of soil wind erosion between different regions ( P<0.05 ). When the wind speed is small, there is no significant difference in soil loss between the two different mounds. When the wind speed increased to 12 m·s-1, the soil loss of plateau pika mound was greater than that of plateau zokor mound ( P<0.05 ). When the wind speed increased from 3 m·s-1 to 12 m·s-1, the average increase of soil loss in the two kinds of mounds was 238.16% and 146.31%, respectively. (2) The wind erosion rate of the mound soil in each test area generally showed a decreasing trend from fast to slow. Vegetation coverage was a significant factor affecting the soil loss of the mound under low wind speed and was related to altitude. (3)With the aggravation of grassland degradation, soil total nitrogen content, available nitrogen, available potassium and organic matter content decreased significantly, while total phosphorus, total potassium and available phosphorus showed an upward trend. This study shows that the difference of soil wind erosion in different regions of the Yellow River source is closely related to soil moisture content, particle size and wind speed.
Subjects: Geosciences >> Geography submitted time 2024-06-12 Cooperative journals: 《干旱区研究》
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.
Subjects: Geosciences >> Geography submitted time 2021-04-23 Cooperative journals: 《干旱区研究》
Abstract：以黄河源区的高寒草地为研究对象，探讨了草地和裸地在0~10 cm、10~20 cm、20~30 cm、30~40 cm和40~50 cm 5种不同深度土壤理化性质和根-土复合体抗剪强度特征。研究结果表明：黄河源区的土壤为弱碱性土，且pH值、密度随着土壤深度增加而增大。土壤含水率、有机质随土壤深度的增加表现出减小的变化趋势。与此同时，草地土体粘聚力c 值随深度增加而降低，而裸地则表现出随土壤深度的增加而增大的变化特征。由灰色关联法分析结果表明：草地根-土复合体粘聚力c 值与速效磷、含根量和有机质的关联度相对较高，分别为0.82、0.82、0.76，裸地土体粘聚力c 值则与密度、pH值和土壤颗粒控制粒径d60参数值的关联度相对较高，即分别为0.76、0.74、0.73。研究结果对科学有效防治高寒区因草地退化引起的水土流失、浅层滑坡等灾害现象的发生，具有理论研究价值和现实意义。
Subjects: Geosciences >> Geography submitted time 2020-12-17 Cooperative journals: 《干旱区研究》
Abstract：以青藏铁路沱沱河段取土场作为研究区，选取生长年限为10 a的碱茅[Puccinellia distans (Linn.) Parl.]、垂穗披碱草（Elymus nutans Griseb.）、冷地早熟禾（Poa crymophila L.）和星星草[Puccinellia tenuiflora (Griseb.) Scribn.] 4种草本作为试验供试种，分别进行室内单根拉伸与剪切试验，较为系统地评价了4种草本其单根力学强度特征。结果表明：（1）取土场4种草本单根平均抗拉强度由大至小为：碱茅（66.29 MPa）>垂穗披碱草（50.78 MPa）>冷地早熟禾（46.11 MPa）>星星草（40.62 MPa），单根平均抗剪强度由大至小为：碱茅（44.37 MPa）>垂穗披碱草（37.74 MPa）>冷地早熟禾（36.80 MPa）>星星草（26.66 MPa），且两者均与根径之间符合幂函数负相关关系；（2）对生长年限为5 a和10 a的4种草本单根抗拉力和抗剪力对比分析得出，4种草本根系抗拉力增长幅度为11.71%~62.31%，抗剪力增长幅度为26.30%~92.61%；（3）比较4种草本根系其不同根径级别的力学强度，得出碱茅和垂穗披碱草根系力学性能相对优于其他2种草本，可优先作为研究区固土护坡植物种。本研究可为青藏铁路沱沱河段及周边优势护坡植物的筛选提供一定理论依据。
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