Research on the slope spectrum of the Loess Plateau

Abstract

A new concept dealing with digital analysis of loess terrain, slope spectrum, is presented and discussed in this paper, by introducing its characteristic, representation and extracting method from DEMs. Using 48 geomorphological units in different parts of the loess as test areas and 5 m-resolution DEMs as original test data, the quantitative depiction and spatial distribution of slope spectrum in China's Loess Plateau have been studied on the basis of a series of carefully-designed experiments. In addition, initial experiment indicates a strong relationship between the slope spectrum and the loess landform types, displaying a potential importance of the slope spectrum in geomorphological studies. Based on the slope spectrums derived from the 25 m-resolution DEM data in whole loess terrain in northern part of Shaanxi, 13 slope spectrum indices were extracted and integrated into a comprehensive layer with image integration method. Based on that, a series of unsupervised classifications was applied in order to make a landform classification in northern Shaanxi Loess Plateau. Experimental results show that the slope spectrum analysis is an effective method in revealing the macro landform features. A continuous change of slope spectrum from south to north in northern Shaanxi Loess Plateau shows an obvious spatial distribution of different loess landforms. This also proves the great significance of the slope spectrum method in describing the terrain roughness and landform evolution as well as a further understanding on landform genesis and spatial distribution rule of different landforms in the Loess Plateau.Loess Plateau, slope spectrum, slope, DEM, loess landform

Modeling the evolution of loess-covered landforms in the Loess Plateau of China using a DEM of underground bedrock surface

“…Terrain texture of the two surfaces was evaluated using hill-shading based on the DEMs and algorithm of Burrough and McDonnell (1998). A 3rd-order finite different weight method (Burrough and McDonnell, 1998) was used to calculate the slope angle, and the frequency distribution of slope values was also implemented (Tang et al, 2008). In the current study, the slope aspect (Burrough and McDonnell, 1998) was also calculated and a numerical statistical analysis was completed for eight different directions, N, NE, E, SE, S, SW, W and NW, which were classified to investigate the slope aspect changes.…”

Topographic Spatial Variation Analysis of Loess Shoulder Lines in the Loess Plateau of China Based on MF-DFA

“…The Loess Plateau of China has drawn the attention of many researchers worldwide for its unique geographical condition, geomorphologic research values, loess landform feature, and its special natural and cultural landscapes [1,2]. Many previous studies about the Loess Plateau have been carried out to solve scientific problems regarding its formation process [3,4], landform shape [5][6][7], gully development [8][9][10], soil erosion [11,12], environmental evolution [13,14] etc., and many outstanding research results have been achieved.…”

“…The terrain points [22][23][24], lines [25][26][27], and surfaces [28][29][30] studies mainly focused on research with the view of developing and evaluating technologies and methods, and there is a lack of research and discussion on the role of terrain data in the study of the topography and geomorphology of the Loess Plateau. Tang et al [1] established the theory of the slope topo-sequence, which they successfully applied to study the Loess landform. The corresponding slope topo-sequence, which showed an obvious spatial distribution, of any of the different Loess landforms could be found [31].…”

Extraction of Terraces on the Loess Plateau from High-Resolution DEMs and Imagery Utilizing Object-Based Image Analysis

“…It is attributed to that the landform of the Loess Plateau has spatial heterogeneity, including different landform sub-types [58]. However, this heterogeneity has certain regularity [28,59]. Therefore, the proposed method can be applied to a certain area with a same landform sub-type due to the landform self-similarity.…”