Conceptual Model of Terrain Texture in Loess Plateau based on DEM

The geomorphic characteristics of "thousands of gullies" in the Loess Plateau show significant self similarity in multi-scale space, and have obvious textural characteristics of local-irregular and macro-regular. Previous studies have shown that there have been specific research results on the selection of texture features, the uncertainty of scale effect, and the combination of texture features with other features in identification and classification of specific landforms. However, the current texture analysis methods are limited to the application of macro terrain classification. For the concept, classification, basic characteristics, and analysis methods of terrain texture, there is a lack of theoretical framework for application support. On the basis of the existing research results, this paper defines the Loess Plateau as the research scope, and puts forward the concept model of the Loess Plateau terrain texture, namely definition, characteristics, classification, and expression. In terms of the definition of terrain texture, this paper expands the scope of the definition. In addition to the existing macro morphological topographic texture, the terrain texture formed by the combination of the characteristics of typical loess geomorphic units (loess yuan, liang, mao, etc.) and the terrain texture formed by the slope characteristics of loess slope are proposed. This paper points out that the data expression based on Digital Elevation Model (DEM) will be more conducive to the quantification of terrain texture, especially the terrain factor derived from DEM can expand the feature space of terrain texture and enrich the data source of terrain texture analysis. In terms of the basic features of terrain texture, this paper puts forward three basic characteristics: regional difference, genetic complexity, and scale dependence. Among them, regional differences can be qualitatively distinguished by visualization or quantified by existing statistical methods, so as to effectively distinguish differences in texture between regions. In the classification system of terrain texture, this paper classifies the terrain texture based on its element saliency, texture origin, and visual form. Taking loess liang in the loess hilly and gully region as an example, a single loess liang can be regarded as a texture element. Through a certain arrangement and combination of several loess liang, the terrain textural characteristics of the loess liang hilly and gully region are formed. However, a single loess liang cannot express the texture features. This paper aims to build a conceptual model of terrain texture oriented to the Loess Plateau, and promotes the application and development of texture analysis method in Loess Plateau. © 2021, Science Press. All right reserved.