地理学报 ›› 1995, Vol. 50 ›› Issue (3): 234-239.doi: 10.11821/xb199503005

• 论文 • 上一篇    下一篇

论坡面侵蚀的临界坡度

靳长兴   

  1. 中国科学院国家计划委员会地理研究所, 北京 100101
  • 收稿日期:1993-03-01 修回日期:1994-11-01 出版日期:1995-05-15 发布日期:1995-05-15
  • 基金资助:
    自然科学重点基金

A THEORETICAL STUDY ON CRITICAL EROSION SLOPE GRADIENT

Jin Changxing   

  1. Institute of Geography. Chinese Academy of Sciences. Beijin 100101
  • Received:1993-03-01 Revised:1994-11-01 Online:1995-05-15 Published:1995-05-15

摘要: 尽管对坡面水力侵蚀中的临界坡度已作了大量研究,但对临界坡度的大小目前仍无一致结论。本文从坡面流的能量理论出发,对临界坡度进行了研究。结果表明,在流量一定时临界坡度在24°-29°之间,其大小视坡面水深与大于等于84%的坡面颗粒的粒径而定。这一结果与众多室内外试验结果一致,从而从理论上解决了临界坡度的大小问题。

关键词: 临界坡度, 侵蚀, 能量

Abstract: The effect of slope gradient on soil erosion has been studied extensively. A common result is that the amount of sheet erosion increases with the increasing of slope gradient. However, to a certain critical slope gradient. the amount of erosion decreases, because the increasing of the slope gradient decreases the actual project area of slope under a certain slope length and thus decreases the amount of flow on slope and the erosivrty of slope runoff. For a long time. scientists have attempted to determine the value of the gradient by both experiment and theory. Laboratory and site experiments give a common critical gradient of about 25?. but the theoretical results were different.In this paper. sheet erosion was supposed to be proportional to the flow energy exhausted to overcome the friction force of slope ground on the flow. The maximum energy exhausted produces the greatest amount of erosion. By solving the equation of energy it was found that the critical slope gradient is between 24癮nd 29?. depending on the ratio of flow depth to the diameter of soil grains which are equal or great than 84% in soil particle composition. The result is in consistent with the experimental result.

Key words: Critical slope gradient, soil erosion, energy

中图分类号: 

  • S157.1