Development of Lineament Extraction Method based on Topography Characteristics and Segment Tracing Algorithm (STA) using Digital Elevation Model

Abstract

The Segment Tracing Algorithm (STA) is one of the effective methods for lineament extraction using DEM (Digital Elevation Model). However, the lineaments extracted by STA are the limited linear structures on the shadedrelief image derived from DEM and are not directly related with the topographical characteristics. In this study, we developed a lineaments extraction method using the line segments discriminated by the topographical characteristics of DEM based on the principle of STA in order to more directly extract lineaments related faults and flexures. The lineament extraction consists of the following five steps: ① calculation of the unit normal vector of topographic surface in each cell of DEM, ② determination of the direction of high continuity with less change of the unit normal vector direction, ③ extraction of the line segments, ④ connection of the line segments, and ⑤ integration of the lines. As a case study, the developed method has been demonstrated for the Rokko Mountains area, and it could be confirmed that there are lineaments coincided with known active faults. The effects of parameters such as size of small window on the extraction of lineaments have been discussed.