Expert-driven semi-automated geomorphological mapping for a mountainous area using a laser DTM

• Published in: Geomorphology (Amsterdam, Netherlands) Vol. 78; no. 3; pp. 309 - 320
• Main Authors: van Asselen, S., Seijmonsbergen, A.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.08.2006; Elsevier
• Subjects: Areal geology. Maps; Bgi / Prodig; Earth sciences; Earth, ocean, space; Exact sciences and technology; Geologic maps, cartography; Geomorphological mapping; Geomorphology; Geomorphology, landform evolution; Laser DTM; Marine and continental quaternary; Methods and techniques; Mountainous area; Object-oriented classification; Physical geography; Surficial geology; Central Europe; Austria; Mountainous area; Object-oriented classification; Geomorphological mapping; Laser DTM; cliffs; mountains; mass movements; laser methods; maps; Europe; accuracy; alluvial fans; slopes; classification; geomorphologic maps; landforms; channels; digital terrain models; terraces; slope angle; landform evolution; high resolution; Mountain; Classification; Forest; Geomorphometry; Digital elevation model; Automated mapping
• ISSN: 0169-555X; 1872-695X
• DOI: 10.1016/j.geomorph.2006.01.037

In this paper a semi-automated method is presented to recognize and spatially delineate geomorphological units in mountainous forested ecosystems, using statistical information extracted from a 1-m resolution laser digital elevation dataset. The method was applied to a mountainous area in Austria. First, slope angle and elevation characteristics were determined for each key geomorphological unit occurring in the study area. Second, a map of slope classes, derived from the laser DTM was used in an expert-driven multilevel object-oriented approach. The resulting classes represent units corresponding to landforms and processes commonly recognized in mountain areas: Fluvial terrace, Alluvial Fan, Slope with mass movement, Talus slope, Rock cliff, Glacial landform, Shallow incised channel and Deep incised channel. The classification result was compared with a validation dataset of geomorphological units derived from an analogue geomorphological map. For the above mentioned classes the percentages of correctly classified grid cells are 69%, 79%, 50%, 64%, 32%, 61%, 23% and 70%, respectively. The lower values of 32% and 23% are mainly related to inaccurate mapping of rock cliffs and shallow incised channels in the analogue geomorphological map. The accuracy increased to 76% and 54% respectively if a buffer is applied to these specific units. It is concluded that high-resolution topographical data derived from laser DTMs are useful for the extraction of geomorphological units in mountain areas.