• 论文 •

泥石流流域集水区面积限值与一级水系数目关系

1. 1. 中国科学院、水利部成都山地灾害与环境研究所, 四川 成都 610041;
2. 北京大学湍流和复杂系统国家重点实验室, 北京 100871
• 收稿日期:2004-06-21 修回日期:2004-10-20 出版日期:2005-07-20 发布日期:2005-07-20
• 基金资助:
国家自然科学基金(40101001)、中国科学院成都山地灾害与环境研究所青年种子基金(2003)的资助。

Relationship Between First-order Stream Number and Area Threshold for Debris Flow Basin

HU Kai-Heng1,2, LI Yong1, WEI Fang-Qiang1

1. 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, Sichuan 610041;
2. State Key Laboratory for Turbulence and Complex Systems, Beijing University, Beijing 100871
• Received:2004-06-21 Revised:2004-10-20 Online:2005-07-20 Published:2005-07-20

Abstract: Drainages can show more complex structure at the smaller scale, which is the representation of the corresponding basin's self-similarity. The detailed structures for different debris flow basins reflect their ability to transport material, which suggests that the small-scale structure plays an important role in the debris flow formation. Therefore, the paper focuses on the drainage hierarchical characteristic of debris flow basin, and two basin parameters (first-order stream number and area threshold) are used to examine this characteristic because the two are not affected by stream ordering methods and DEM errors. Three typical debris flow basins with different catchment area (Jiangjia, Longdong and Guxiang Ravine) were studied, which respectively located in three distinct regions. Using hydrological analysis tool in ArcInfo software the stream networks with different catchment area thresholds were extracted from these basins' DEM and one set of first-order subbasin was identified. It is obvious that these subbasins occupy the whole basin's fringe region where mass transportation starts. So this suggests that the subbasins play an important role in the initiation and material supply of debris flows. Another point is that the number of extracted first-order stream decreases rapidly with the area threshold increasing. It is found that the two parameters have close relation N=RA(a/m) have close relation, and exponent a equals to-1 and coefficient k only relates to the total basin area, namely for the same basin the product of first-order number with area threshold is constant in a wide scale range. The relationship may show that the ability of debris flow basin to transport material doesn't change in so wide scale range. Further research will be paid more attention to the distinction of exponent a and coefficient k between debris-flow basin and non-debris-flow basin.

• P333.9