地球信息科学学报 ›› 2020, Vol. 22 ›› Issue (3): 442-451.doi: 10.12082/dqxxkx.2020.190555

• “数字地形分析”专栏 • 上一篇    下一篇

基于地形剖面的黄土塬梁峁地形各向异性奇异强度研究

曹建军1,2,*(), 汤国安2, 方炫1,2, 刘永娟1, 那嘉明2, 朱莹1, 李金莲1   

  1. 1. 南京晓庄学院环境科学学院,南京 211171
    2. 虚拟地理环境教育部重点实验室(南京师范大学),南京 210023
  • 收稿日期:2019-09-27 修回日期:2019-12-08 出版日期:2020-03-25 发布日期:2020-05-18
  • 通讯作者: 曹建军 E-mail:jjcao@njnu.edu.cn
  • 作者简介:曹建军(1976— ),男,陕西延安人,博士后,主要从事地形空间关系研究。E-mail:jjcao@njnu.edu.cn
  • 基金资助:
    国家自然科学基金项目(41930102);国家自然科学基金项目(41871313);国家自然科学基金项目(41671389)

Study on the Singularity Strength of Topographic Anisotropy of Loess Tableland, Ridge, Hill in Loess Plateau based on Terrain Profile

CAO Jianjun1,2,*(), TANG Guoan2, FANG Xuan1,2, LIU Yongjuan1, NA Jiaming2, ZHU Ying1, LI Jinlian1   

  1. 1. School of Environmental Science, Nanjing Xiaozhuang University, Nanjing 211171, China
    2. Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Nanjing 210023, China
  • Received:2019-09-27 Revised:2019-12-08 Online:2020-03-25 Published:2020-05-18
  • Contact: CAO Jianjun E-mail:jjcao@njnu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(41930102);National Natural Science Foundation of China(41871313);National Natural Science Foundation of China(41671389)

摘要:

黄土高原不同地貌类型对应的地形起伏变化特征各不相同,地形起伏在不同方向上的变化特征具有很大差异性,即地形各向异性。本文引入多重分形谱参数描述不同地貌类型地形各向异性的变化规律,以反映不同黄土地貌地形各向异性的局部和整体变化格局。本研究以5 m分辨率的DEM数据为基础,选取淳化、甘泉、绥德3个典型黄土塬梁峁地貌类型研究样区,对其地形各向异性的变化特征进行分析。研究表明:①3种黄土地貌类型地形各向异性变化具有显著的多重分形特征,地形各向异性变化的奇异强度由强到弱依次为淳化、绥德、甘泉;②淳化样区地形各向异性奇异强度在1.4的概率最大,在奇异强度为2.2附近又有一个小的峰值,总体以奇异强度1.4为主;③甘泉样区的奇异强度在1.8有一个小的峰值,总体以奇异强度0.7为主;④绥德样区奇异强度为0.8的概率最大,且较为均匀地分布在0.8附近,地形各向异性的概率分布呈现为对称分布。研究结果为黄土塬梁峁地形各向异性变化奇异强度为黄土塬最大,黄土峁次之,黄土梁最小。该研究可为黄土地貌的精确分类提供定量信息支持,为区域水土侵蚀评价提供地形指标。

关键词: 地形各向异性, 奇异强度, 地形剖面, 地形起伏, 多重分形去除波动趋势分析, 概率分布, 黄土地貌, 黄土高原

Abstract:

The characteristics of topographic relief variation are diverse from one landform type to another in the Loess Plateau. Great differences of topographic relief variation exist in different directions, which is known as topographic anisotropy. As fractal theory and geomorphology research become increasingly cooperative, Multifractal Detrended Fluctuation Analysis (MF-DFA) method, an effective means to quantitatively describe the nonlinear evolution process of complex sequences and the self-similar structural features formed by nonlinear evolution processes, manifests great potential in the study of topographic anisotropy of different landforms. In this paper, multifractal spectrum parameters were introduced to describe the variation characteristics of topographic anisotropy, in order to illustrate the local and global variation pattern of topographic anisotropy of different loess landforms. Based on 5 m-resolution Digital Elevation Model (DEM) data, three typical areas, Chunhua County of loess tableland, Ganquan County of loess ridge and Suide County of loess hill, were selected as the study areas. After that, MF-DFA of the variation characteristics of topographic anisotropy were conducted on these three areas. The results show that the topographic anisotropy of the three loess landform types has significant multifractal characteristics. The singularity strength of the topographic anisotropy from strong to weak turns out to be in the order of Chunhua, Suide and Ganquan counties. The probability of the singularity strength of topographic anisotropy in Chunhua County reaches the maximum at singular strength of 1.4, and there is a small peak around the singularity strength of 2.2. The probability of the singularity strength of topographic anisotropy in Ganquan County reaches the maximum at singularity strength of 0.7, with a second peak around the singularity strength of 1.8. Differently, the singularity strength of topographic anisotropy in Suide County is evenly distributed around 0.8, reaching the maximum at singularity strength of 0.8. The overall singularity strength of Chunhua and Ganquan counties are 1.4 and 0.7 respectively, while the probability distribution of topographic anisotropy in Suide County appears symmetrically. It can be concluded that the singularity strength of the topographic anisotropy is the highest in loess tableland, followed by that in loess hill. The singularity strength of the topographic anisotropy is the smallest in loess ridge. The results confirm that multifractal singularity strength is an effective method for the description and analysis of the topographic anisotropy of loess landforms, e.g., tableland, ridge and hill. This study can provide quantitative information support for the accurate classification of loess landforms as well as topographic indicators for regional water and soil erosion assessment.

Key words: topographic anisotropy, singularity strength, terrain profile, topographic relief, MF-DFA, probability distribution, loess landforms, Loes Plateau