Measure Of Terrain Complexity In The Hilly And Gully Area Of Loess Plateau Based On DEM

Terrain complexity is an important parameter of topographic differentiation in the field of geosciences.It is used to describe the overall characteristics of topographic differences and has important application significance and value in digital terrain analysis,land classification,ecology and other related fields.Terrain complexity itself is an abstract concept.Many concepts measured in degrees are often relative.At present,there is no unified and comprehensive definition and measurement index for terrain complexity.For the quantif ication of terrain complexity,most scholars measure the degree of terrain complexity according to the variation law of terrain factors.For the problem that terrain complexity is difficult to quantify accurately,the paper proposes two kinds of terrain complexity evaluation based on single factor and multi-factor.Methods:Using terrain analysis method and fractal theory,the four factors of contour line value,surface gradient,topographic feature point and topographic relief degree were selected.Sexual processing,analysis and evaluation of terrain complexity in the study area.The results of the study show that the spatial distribution of terrain complexity is similar to the variation of terrain complexity factor.The study area of this paper is located in the center of the Loess Plateau and belongs to the loess hilly and gully region.The loess hilly and gully region has a wide distribution area.Although all the research areas belong to the hilly and gully region of the Loess Plateau,the landforms are different.For the complex terrain environment in the loess hilly-gully region and the fragmented surface structure,the paper selects Ningxia.The southern part of the loess hilly gully region-Xiji County,as the study area of the paper.According to the complexity of each factor,the factors were analyzed theoretically and measured experimentally.It is demonstrated that all four factors can quantify the complexity of the terrain.The difference is that the degree of terrain complexity reflected by each factor is different,or the scale of influence is different.This study has theoretically enriched the application of fractal theory in geosciences,and also summarized the factors that can be selected or referenced when calculating terrain complexity.