地理科学进展 ›› 2002, Vol. 21 ›› Issue (2): 103-110.doi: 10.11820/dlkxjz.2002.02.002

• 论文 • 上一篇    下一篇

地形指数的物理意义分析

邓慧平1, 李秀彬2   

  1. 1. 南通师范学院地理系,南通226007;
    2. 中国科学院地理科学与资源研究所,北京100101
  • 收稿日期:2002-01-01 修回日期:2002-02-01 出版日期:2002-03-24 发布日期:2002-03-24
  • 作者简介:邓慧平(1962-),男,江苏人,博士。主要从事气候和土地覆被变化的水文影响研究。E-mail:denghp 62@sina.com
  • 基金资助:

    中国科学院知识创新工程项目(KZCX2-310,KZCX1-Y-02)

Relationship of Upslope Contribution Area and Soil Water Content in TOPMODEL

DENG Hui ping1, LI Xiu bin2   

  1. 1. Nantong Normal College, Nantong 226007 China;
    2. Institute of Geographical Sciences and Natural Resources Research,CAS, Beijing 100101 China
  • Received:2002-01-01 Revised:2002-02-01 Online:2002-03-24 Published:2002-03-24

摘要: 地形指数模型 ( TOPMODEL)用地形指数在流域中的空间格局来确定流域饱和缺水量的空间分布和产流区的空间位置与范围 ,物理意义明确。本文介绍了地形指数的物理基础及其与土壤水分的关系。分析了地形指数空间变化与汇流面积 a及局地坡度空间变化的关系 ,a范围内有效汇流面积的变化 ,提出了一种确定 a上限值的方法。

关键词: 地形指数, 地形指数计算, 梭磨河流域, 物理意义, 有效汇流面积

Abstract: Topography-based hydrological models (TOPMODEL) make use of topographic information and the spatial distribution of topographic index (ln a /tan β ) to represent the soil water storage deficit below saturation and spatial variability of contributing area. In this paper, the physical basis of the index and its relationships with soil water storage are introduced. The effects of spatial change of drainage area ( a ) and local slope β on the spatial change of the index are analyzed. The changes of effective upslope drainage area with soil water condition are discussed. Finally, by using a 100 m×100 m DEM and single flow direction algorithm, the index distribution functions are calculated for Sumo basin on upper reaches of the Yangzi river under different channel initiation threshold. An assumption of TOPMODEL is that there is a saturated zone in equilibrium with a steady recharge rate over an upslope contributing area a . This makes TOPMODEL appropriate only for humid areas. To break this assumption, the authors argue that two concepts, i.e., effective contributing area and maximum contributing area, should be distinguished. The effective contributing area indicates the area ( a , the maximum contributing area) with soil water content over field capacity according to the theory underlying the model. The authors also propose a method to calculate Channel Initiation Threshold (CIT) in order to derive a reasonable distribution of topographic index in a watershed. The CIT is usually not easy to define because of the variation of slope length with terrain type. The authors suggest that the CIT should be defined according to a GIS analysis of statistical distribution of slope length in the study watershed.

Key words: Effective drainage area, Index calculation, Physical meaning, the Sumo basin, Topographic index

中图分类号: 

  • P208