Research Topics

The research topics that I worked with my students range from landslide topography, effective 3D geologic mapping, landslide modeling, and structural geology & continental tectonics. I mainly emphasize on a research direction that requires high-resolution digital elevation models (DEM) for new insights on various topics on surface processes and geologic structures. Here I list four major topics that best represent my recent research contributions.

(I) Applications of multi-period and multi-source high-resolution DEMs for studies of landslide and erosion processes

The increasing number of DEMs from various sources has posed unsettling questions on how to reliably estimate errors, particularly, when difference of DEMs is performed. We used different periods of digital terrain model (DTM) data obtained from various flight vehicles by using the techniques of aerial photogrammetry, airborne LiDAR (ALS), and unmanned aerial vehicles (UAV) to discuss errors and proper applications. We found that multi-period aerial photogrammetry and ALS can be effectively applied after the landslide disaster for monitoring the terrain changes and their potential impacts downstream.

(II) Problems and solutions in high-resolution geological mapping using LiDAR data in 3D environments

Traditional geological mapping is highly dependent on field investigation, which is usually a time-consuming and challenging task for field geologists. The full potential of LiDAR-derived high-resolution DEMs remains to be explored in geological mapping using 3D rendering techniques. Through field verification and assessment, manipulation of the LiDAR data with relevant 3D visualization is shown to be an effective approach to improve the correctness and details of existing geological maps. The proposed methodology provides a breakthrough for our advanced work in high-resolution geological mapping in 3D environments.

(III) Deformation patterns and structural development of active mountain belts

Located in northern Vietnam, the Fansipan mountain range is the highest topography in the Indochina area. Until recently, there has been limited research regarding the tectonic deformation of the Fansipan mountain range and whether there are notable surface ruptures or active faults in the area. Our study provides the frst insight into the deformation patterns and potential active movements of the Fansipan mountain range, and may improve our understanding of the overall tectonic activities in northern Vietnam. For the Taiwan mountain belt, basal accretion is considered responsible for the distinct culmination of the Hsüehshan Range in central Taiwan and its relative uplift with respect to the Backbone Range to the east along the Lishan Fault. We propose that basal accretion is the predominant mechanism in the growth and evolution of the Taiwan orogenic wedge and may have been achieved through inversion of a graben system on the ancient passive margin during continental subduction.

(IV) Assessing the landslide process and its potential hazard by monotoring and modeling

Landslides are one of the most serious natural hazards and have caused serious property damages and life losses in Taiwan. I have started the line of research in modeling landslide processes tapping into the LiDAR data and computing powers in recent years. We monitored and modeled catastrophic slope failure under heavy rainfall conditions. The work by the 3D discrete element method provides potential runout paths, particle velocities and landslide-affected areas, which are useful information for decision support and hazard assessment.