Terrain Skeleton Construction and Analysis in Loess Plateau of Northern Shaanxi

Yuanyuan Zhao,Xu Su,Wen Dai,Chun Wang,Min Li,Weitao Li,Ting Wu

doi:10.3390/ijgi11020136

Abstract

A terrain skeleton determines the overall structure and characteristics of the terrain and indicates the presence of significant terrain features, such as ridges and valleys. It plays an important role in terrain representation and reconstruction, hydrological analysis of watersheds, and other scientific studies and engineering applications. Previous studies of terrain skeleton have been mostly focused on the extraction of terrain skeletons, ignoring their important effect on terrain analysis. Therefore, this work proposes a new terrain skeleton, which includes three types of terrain skeleton points and two types of terrain skeleton lines. The terrain control points are peak, saddle, and valley nodes, while the terrain skeleton lines are connection lines of peaks and saddles and connection lines of saddles and valley nodes. The terrain skeleton connects isolated terrain control points together. The data structure is designed, and three analysis indicators, namely, nearest-neighbor index, topological connectivity index and landscape shape index are selected. Results show that the three selected indicators can reflect the spatial structure of the terrain skeleton and describe the landform development to a certain extent. Different areas of the same landform, such as the two sample areas in Shenmu County, show variations.

Highlights

The formation of the terrain skeleton affects the overall structure and characteristics of the terrain, and it is the controlling link in the description of the terrain’s morphological structure and formation [1,2,3]
This study aims to: (1) develop a method for the reconstruction of a terrain skeleton by considering the relationships of skeleton features; and (2) analyze the characteristics of the terrain skeleton in the northern Loess Plateau of Shaanxi province, China
The study area is located in the Loess Plateau of northern and middle Shaanxi Province in China, which is a complex geomorphology formed by severe water and wind erosions

Summary

Introduction

The formation of the terrain skeleton affects the overall structure and characteristics of the terrain, and it is the controlling link in the description of the terrain’s morphological structure and formation [1,2,3]. A terrain skeleton indicates the presence of significant terrain features, such as ridges and valleys [4,5], which are the dividing lines of mountain topography. Many studies have been conducted on the extraction of terrain control points [9], including local height-difference comparison method [10,11], mathematical surface fitting method [12] and runoff simulation method [13,14]. The extraction of ridges and valleys, which as two important terrain feature lines have aroused widespread concern. Tang classified these methods according to data sources and algorithm principles [15]. There are methods based on terrain surface flow direction analysis [25], image processing technology [22,26], surface geometry analysis [20,27], and the combination of the terrain surface geometry analysis and flow physical simulation analysis according to the different algorithm principles [28,29]

Objectives

Methods

Conclusion