Using terrestrial LiDAR to accurately measure the microgeomorphologic geometry of active fault: A case study of fault scarp on the Maoyaba fault zone

Abstract

The micro-geomorphologic geometry of active fault is often complex due to the natural dynamics, such as high degree of sedimentation and erosion, and man-made activities. It is difficult for traditional measurement methods to quickly and efficiently obtain the high-precision geomorphological geometry of fault scarp and to acquire fault displacement in a large scale. Light Detection And Ranging (LiDAR) provides a new technology for the quantitative study of the micro-geomorphologic geometry of active fault. In this study, the high-precision point cloud data of micro-geomorphologic geometry of the fault scarp are obtained by the terrestrial LiDAR on the Maoyaba fault. After the registration, filter, resample and irregular triangular mesh modeling processing of the point cloud data, the 0.05 m high-resolution DEM and the true color three-dimensional model are generated. On this basis, the geomorphic features of the fault scarp are analyzed, and the vertical displacements of two landforms produced by the latest two periods of normal faulting are obtained. The results show that the terrestrial LiDAR technology is an effective method to accurately measure the micro-geomorphic morphology of active fault and to quantify the relevant geomorphic characteristic parameters, which improves the precision and understanding level of the micro-geomorphologic geometry of active fault.

Keywords

• maoyaba fault
• point cloud
• fault scarp
• dem
• vertical displacement