A tool for semi-automatic linear feature detection based on DTM

The tectonic movement along faults is often reflected by geomorphological features such as linear valleys, ridgelines and slope-breaks, steep slopes of uniform aspect, regional anisotropy and tilt of terrain. In the last years, remote sensing data have been used as a source of information for the detection of tectonic structures. In this paper, a new fully 3D approach for semi-automatic extraction and characterization of geological lineaments is presented: linear features are detected on a DTM by means of algorithms based on principal curvature values, and then they are grouped according to data collected from literature review regarding expected orientation of lineaments in the studied area. The overall positive aspects of this semi-automatic process were found to be the informativeness on geological structure for preliminary geological assessment and set identification, the possibility to identify the most interesting portions to be investigated and to analyze zones that are not directly accessible. This method has been applied to a geologically well-known area (the Monferrato geological domain) in order to validate the results of the software processing with remotely sensed data collected from literature review. As regard to orientation, spatial distribution and length of the lineaments, the study demonstrates a correspondence of the obtained results with both remote sensed linear features and field geostructural data.