[1]YU Dongmei,QI Zhaoxin,LIU Yabin,et al.Factors Affecting Shear Strength and Contribution Evaluation of Root-Soil Composite Systems of Five Halophytes in the Salt Lake Region of Northwest Qaidam Basin, Qinghai Province[J].Research of Soil and Water Conservation,2019,26(04):157-165.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
26
Number of periods:
2019 04
Page number:
157-165
Column:
Public date:
2019-06-11
- Title:
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Factors Affecting Shear Strength and Contribution Evaluation of Root-Soil Composite Systems of Five Halophytes in the Salt Lake Region of Northwest Qaidam Basin, Qinghai Province
- Author(s):
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YU Dongmei1,2, QI Zhaoxin1,3, LIU Yabin1,3, YANG Youqing1,3, LI Shuxia1,3, HU Xiasong1,2,4, FU Jiangtao1,2,3
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1. Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China;
2. Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes, Xining 810008, China;
3. University of Chinese Academy of Sciences, Beijing 100049, China;
4. Qinghai University, Xining 810016, China
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- Keywords:
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Qaidam Basin; Gasikule Salt Lake; halophytes; root-soil system; grey correlation method
- CLC:
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S152;S153
- DOI:
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- Abstract:
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To explore the factors which affect shear strength of five halophyte root-soil composite systems and the characteristics of shear strength, the region around the Gasikule Salt in Qiadam Basin was selected as the test site. First, five predominate indigenous plant species such as Phragmites australis Trin., Triglochin maritimum Linn., Carex enervis C. A. Mey., Leymus secalinus (Georgi) Tzvel., Koeleria cristata (L.) Pers. were taken as test plants; then indoor direct shear tests were conducted on the rooted soil of the five species to investigate the effects of such factors as Bulk density, moisture content, root length density, root weight density, and root area ratio on the shear strength of rooted soil; finally, based on the above tests, grey correlation method was adopted to further evaluate the degrees of the effects of these factors on the shear strength of rooted soil. The results have testified the grey correlations of cohesion force (c) and internal friction angel (φ) with the factors, that is, the correlation of bulk density to c and φ is 0.740 and 0.879, 0.698 and 0.849 for moisture content, 0.692 and 0.609 for root weight density, 0.655 and 0.519 for root length density, 0.631 and 0.569 for root area ratio; among the five factors, there is a significant correlation between bulk density and shear strength of rooted soil for the five species. Phragmites australis root enhancing soil cohesion c value is relatively significant because the root system is approximately vertical in the soil. Therefore, most of the roots in the sample pass through the shear plane, that is, when the composite shear deformation occurs, the root system in the sample can basically play a role in resisting shear deformation. The results can be significance of preventing water and soil loss and controlling shallow landslides and other natural disasters in the areas with similar geological and climatic conditions.