基于DEM与DLG的福建省地貌形态自动分类

以福建省1:10万的DLG(Digital Line Graphic,数字线划图)和DEM(Digital Elevation Model,数字高程模型)为基础,在ArcGIS软件支持下,依据坡度和面积组合指标,将福建省地貌形态单元分为平缓地和山丘地;提取地形图中水系与等高线的高程点交集,构建了福建省地方相对基准面,并以流域水文分析方法提取了山丘地地貌形态实体单元;把平缓地和山丘地貌形态实体单元分别与地方侵蚀基准面叠加,参照"中国1:100万地貌制图规范",将福建省地貌形态类型分为平地、台地、低丘、高丘、低山、中山。研究结果表明:该方法符合福建传统地貌分类体系,能够较好快速实现平缓地与山丘地、平地(平原)与台(阶)地的自动划分,有效地提取山丘地貌形态实体单元的界线。

Auto-Classification of Geomorphological Types Based on DLG and DEM for Fujian Province

Base on Digital Line Graphic (DLG) at 1:100,000 scale and Digital Elevation Model (DEM: 30×30 m resolution), firstly, the geomorphological types of Fujian Province can be divided into two basic types according to the two main combinational indicators slope and area: shallow-slope region and hill-mountain (steep-slope) region. Secondly, the elevational points that contours the river system in DLG are extracted by ArcGIS software. On this basis, the relative reference surface of Fujian Province is constructed through spacial interpolation method. Thirdly, geomorphological entities in steep-slope region are divided into taper units with the method of watershed hydrological model. Finally, according to the 1:1,000,000 Geomorphological Mapping Specification for China, combining the geomorphological characteristics of Fujian Province, and overlaying the above-mentioned geomorphological entities and relative reference surface of Fujian Province respectively, the geomorphological entities of Fujian Province can be divided into six types, i.e., plain, platform, low relief hill, high relief hill, low relief mountain and intermediate relief mountain. The result shows: among geomorphological types of Fujian Province, hill accounts for 34.1%, mountain accounts for 51.8%, both together account for 85.9%, and plain, flat and platform together account for only 13.1%. The result is basically identical to that by traditional manual mapping. The methods developed in this article are corresponding to traditional classification system of geomorphology for Fujian, and can automatically classify the geomorphological entities fast and well, such as the shallow-slope region and hill-mountain region, plain and platform, which are feasible according to precision and efficiency, saving manpower, material resources and financial resources greatly, and offering a new thinking and methodology for domestic and international similar researches.