基于DEM的流域地形因子提取与量化关系研究——以陕北黄土高原的实验为例

Research on the topographic factors and its' mathematical simulation based on DEMs-a case study in the loess plateau of north Shaanxi province

地貌的形成是一个漫长的系统过程,其形态可以看成是表征其特征的各种地形信息因子复合在一起的复杂函数。以黄土高原地区的6个典型地貌区作为试验区,基于1∶10000比例尺5m分辨率的高精度DEM数据,在实现自然地理单元———小流域自动分割的基础上,随机选取44个完整小流域,完成了区域内沟壑密度、平均坡度、平均坡长和地形起伏度等基本地形信息因子的自动提取;同时,采用比较分析和数理统计的方法,证明沟壑密度与平均坡度、平均坡长和地形起伏度之间存在着很强的线性相关关系,量化模拟结果显示,沟壑密度(Y)可以表示为平均坡度(X1)、平均坡长(X2)和相对高差值(X3)的函数:Y=2.95228+0.127906X1-0.014X2-0.00273X3,模拟精度为94.5%。该方法对于整体研究黄土高原及其他地貌的形态特征和成因机理,具有重要的理论和实践意义。

Types of geomorphology forming is a systematic process,and the form can be seemed as a function compounding different topographic factors.Based on 1:10000 scaled DEM,choosing 6 classic test areas in the Loess Plateau,taking gully density as following variable and mean slope,mean flow length and relief as independent variable,this article stimulates their quantitative relation.The result of research proves that the four topographic factors have strong linear relation,and the mathematical relation have important theoretical and practical significance to research causing and configuration characters of geomorphology of the Loess Plateau.