A Systematic Classification Research of Topographic Descriptive Attribute in Digital Terrain Analysis

Topographic attributes (TAs) play an important role in quantitatively describing the characteristics of landform and its structure. At present, TAs are classified from different views by many scientists being from various fields. However, there are still some urgent problems that need to be clarified about TAs. The relationships and differences of various TAs are not revealed and a mature, widely accepted and systematic classification has not been established. Based on previous research, TAs are systematically classified in this paper, taking consideration of systematic, hierarchical and practical principles. Firstly, TAs can be divided into global TAs and local TAs in the light of their descriptive spatial extent. Secondly, according to their algorithms, TAs are classified into basic TAs, compound TAs, features TAs and statistical TAs. Thirdly, TAs are distinguished into morphologic TAs and structural TAs according to their descriptive themes. Fourthly, on the basis of the relationship of TAs values and coordinate axes direction, TAs are grouped into geometrical TAs, isotropic TAs, axial TAs, and anisotropic TAs. Moreover, TAs can be labelled as first-order TAs, secondorder TAs and multiple-order TAs by partial derivatives degree of elevation data. Being parameters of landform characteristics, TAs are the basis of quantitative geomorphologic research and essential indices that differentiate landform areas. So the classification is helpful in understanding the exact semantic meaning of TAs and their interrelationships for users. And it’s helpful in selecting effectively and reasonably TAs in practice. Besides, it’s helpful in solving some correlative problems in the research of digital terrain analysis. * [email protected]; phone +86-13776623891; fax +86-25-85898270