• “数字地形分析”专栏 •

### 基于DEM的一体化山地特征要素提取

1. 西华师范大学国土资源学院,南充 637009
• 收稿日期:2019-09-28 修回日期:2020-02-17 出版日期:2020-03-25 发布日期:2020-05-18
• 通讯作者: 罗明良 E-mail:lolean586@163.com
• 作者简介:胡金龙（1998— ）,男,四川德阳人,研究方向为GIS及其空间分析。E-mail:ltpai91@hotmail.com
• 基金资助:
国家自然科学基金项目(41871324);四川省科技厅应用基础重点项目(2018JY0464);西华师范大学英才基金项目(17YC115);西华师范大学校级科研创新项目(cxcy2018300)

### The Extraction of Characteristic Elements of Mountain based on DEM

HU Jinlong, TANG Mengge, LUO Mingliang*(), WEI Lan, YAN Zihong, QIN Zihan

1. School of Land and Resources, China West Normal University, Nanchong 637009, China
• Received:2019-09-28 Revised:2020-02-17 Online:2020-03-25 Published:2020-05-18
• Contact: LUO Mingliang E-mail:lolean586@163.com
• Supported by:
National Natural Science Foundation of China(41871324);The Applied Basic Research Programs of Science and Technology Department of Sichuan(2018JY0464);Talent Fund Project of China West Normal University(17YC115);National Science and Technology Innovation Project for College Students of China West Normal University(cxcy2018300)

Abstract:

As a vital source of spatial data, DEM plays an important role in the process of geomorphologic characteristics analysis. DEM provides us an opportunity to study the earth surface with an even broader perspective aided by digital terrain structure analysis. The terrain surface often can be regarded as a combination of some fundamental elements, which include the peaks, ridge lines and valley, etc. The peaks and ridge lines depict the macro relief of the terrain, which explains why they often can be used to reveal the morphology, pattern, and evolution processes of the landform. Although the platform of ArcGIS enables the peaks and ridges to be extracted efficiently, there are still many obstacles in existence on the issue of landform features extraction. Firstly, the peaks and ridges extracted by the existing methods are independent of each other, ignoring the expression of their relationship. Secondly, the peaks often be picked out since they are the highest point in a given neighborhood, but these peaks are not necessarily mountain tops in the geomorphological sense and in cognition of mankind. The Liangshan Plateau Mountain in Sichuan Province is taken as a case study, since it is a typical mountainous area and is a transitional zone between the Qinghai-Tibet Plateau and the southwest edge of Sichuan Basin. A novel integrated strategy is provided in the paper to extract mountain peaks and ridges that are close to human cognition. The first step of the method is to section the terrain to obtain the highest points in every patches and the border of the patches. Then the ridge lines are extracted and ordered by a coding formula. An important step in the process is to identify the main peaks and the major ridge lines and finalize the integration of the peaks, mountain ridge lines and their territory. For the purpose of verification, the peaks and ridges extracted by the fuzzy logic algorithm are also presented in the paper. For the results, there are 9 main peaks in the region, 53 secondary peaks with an average elevation of 2540 m. And then 230 ridge lines are obtained, of which 9 main mountain ridges with an average length of 60 km. Besides, there are 9 mountains with an average area of 1017 km 2. Overall, the mountain system in this area shows a nearly north-south trend. When the fuzzy membership of peaks is between 0.98 and 1, the mountain peaks obtained by the two methods roughly coincide with each other, while the corresponding membership of the ridge lines is between 0.37 and 0.57. When compared with the results obtained by other methods such fuzzy logic method, the advantages of our algorithm are reflected in the better expression of peaks, main ridges and their interrelationships. It is important in helping people understand that where the mountain peak is, and that where the mountain ridge is, and it is from this point that we think our algorithms have achieved a preliminary transition from raster matrix to geographical objects. This study can be applied to assist in the classification of geomorphological types, regional geographic planning, etc.