喀斯特槽谷区不同岩石与坡面夹角下集中流侵蚀水动力学特征
DOI:
作者:
作者单位:

西南大学资源环境学院 三峡库区生态环境教育部重点实验室

作者简介:

通讯作者:

中图分类号:

基金项目:

国家自然科学基金项目(面上项目,重点项目,重大项目),国家重点基础研究发展计划(973计划)


Hydrodynamic Characteristics of Concentrated Flow under Different Angles between Rock and Slope in the Karst Trough Valley Area
Author:
Affiliation:

College of Resources and Environment,Southwest University,Key Laboratory of Eco-environments in Three Gorges Reservoir Region,Ministry of Education

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
    摘要:

    喀斯特槽谷区地表出露岩石与坡面成不同夹角显著改变地表集中水流特性,进而影响地表侵蚀过程。目前,不同岩石与坡面夹角下的坡面集中流侵蚀水动力动态变化过程还不清楚。通过室内模拟放水冲刷试验,研究了6个岩石与坡面夹角角度(30°、60°、90°、120°、150°、180°)、3个坡度(10°、15°、20°)、3个流量(5、7.5、10 L/min)组合条件下喀斯特槽谷区坡面土壤侵蚀率与水动力学变化过程。结果表明:在各岩石与坡面夹角下,随冲刷历时的推延,土壤侵蚀率(E)先波动性减小后逐渐趋于稳定,水流功率(ω)呈波动变化但趋势不明显,单位水流功率(Up)逐渐减小,水流剪切力(τ)和过水断面单位能量(ε)波动性逐渐增大;夹角150°时平均土壤侵蚀率(0.078 kg/(m2·s))最大,随着夹角增大,τ、ω和ε均呈先减小后增大,Up整体呈减小的变化趋势,各夹角下水动力学指标间差异均显著(P<0.05);E、τ、ω和Up随坡度和流量的增大而增大,ε随流量增大而增大,随坡度变化不明显;试验条件下,E与τ(R2=0.603)、ω(R2=0.600)和Up(R2=0.583)间的关系用幂函数方程描述较好,与ε间的关系则用线性方程描述较好(R2=0.294);相比而言,水流剪切力可更好地描述喀斯特槽谷区不同岩石与坡面夹角坡面的土壤侵蚀率。

    Abstract:

    【Objective】The angles formed by the exposed rocks and the slope surface in Karst trough area significantly change the hydrodynamic characteristics of the concentrated flow caused by the surface runoff convergence, and the process of rill erosion is closely related to hydrodynamic characteristics. So it is essential to explore the hydrodynamic characteristics of concentrated flow erosion on slope at different angles between the rocks and slope in the Karst Trough Valley area. 【Method】To that end, an indoor scouring experiment which was designed to have six angles between rock and slope, three slope gradients and three inflow rates was conducted to study variations of soil erosion rate and hydrodynamic parameters.【Result】The results showed that with the scour duration going on, the soil erosion rate first decreased and then tended to be stable, the stream power and the shear stress fluctuated but the trend was not obvious, the unit stream power gradually decreased, the unit energy gradually increased. When the angle was 150°, the average soil erosion rate was the largest, which was 0.078 kg/(m2·s). With the increase of the angles, the shear stress, the stream power and the unit energy all decreased at first and then increased, and the unit stream power decreased as a whole. The differences of hydrodynamic indexes among the angles were significant (P<0.05). Under the experimental conditions, the soil erosion rate, flow shear force, flow power and unit flow power increased with the change of slope gradients and inflow rates, while the unit energy of the flow cross-section increased with the increase of inflow rates, but the change was not obvious with the slope gradients. The differences of hydrodynamic indexes among the angles were significant (P<0.05). The relationship between soil erosion rate and shear stress (R2=0.603), stream power (R2=0.600) and unit stream power (R2=0.583) was better described by power function equation, while the relationship between soil erosion rate and unit energy of flow section was better described by linear equation (R2=0.294). In contrast, it was better to use shear stress to describe the soil erosion rate on the slope with different angles between rocks and slope in Karst Tough Valley area. 【Conclusion】This study may provide a theoretical basis for revealing the hydrodynamic mechanism of concentrated flow erosion under different angles between rocks and slope in Karst Valley area.

    参考文献
    相似文献
    引证文献
引用本文

曾荣昌,张玉启,何丙辉,李天阳,张海香.喀斯特槽谷区不同岩石与坡面夹角下集中流侵蚀水动力学特征[J].土壤学报,,[待发表]
ZENG Rongchang, ZHANG Yuqi, HE Binghui, LI Tianyang, ZHANG Haixiang. Hydrodynamic Characteristics of Concentrated Flow under Different Angles between Rock and Slope in the Karst Trough Valley Area[J]. Acta Pedologica Sinica,,[In Press]

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数: