My research is focused on understanding erosional processes and process interactions in natural systems, with an emphasis on bedrock-alluvial rivers and mass wasting in mountain environments. I work on a range of spatial and temporal scales, with the goal of understanding processes on the event and reach and hillslope scale and then translating that insight to the longer-term landscape scale. My approach revolves around detailed field studies in locations that serve to both inspire and test general geomorphic principles, and I combine both quantitative and qualitative field data with remote sensing and numerical modeling. Current areas of particular interest include extreme events and how they interact with erosion thresholds, coupled channel-hillslope processes, intra-flood dynamics, scaling up from event-based understanding, and mass wasting triggers.
2018 - present: Research scientist, GFZ
2013 - 2018: Postdoctoral Researcher, GFZ
2008 - 2013: Postdoctoral Research Fellow, Department of Geosciences, National Taiwan University
2003-2008: Ph.D, Geology, Massachusetts Institute of Technology
1998-2002: Bachelor of Science with honors in Geology, California Institute of Technology
The Daan River gorge - field study of fluvial erosion processes
This project involves monitoring the evolution of a rapidly eroding bedrock gorge in western Taiwan. The gorge is the result of uplift of the riverbed during an earthquake in 1999. The river is now rapidly incising into this zone of uplift and since 1999 has carved a dramatic bedrock gorge 1200m long and up to ~20m deep. The extremely rapid pace of incision provides an ideal opportunity to study the interactions between uplift, discharge, sediment supply, channel width, and knickpoint propagation. I use repeat terrestrial lidar surveys, UAV surveys, RTK GPS surveys, and aerial photographs to quantify changes in the gorge with high spatial and temporal resolution.
Surface process effects of the 2015 Gorkha Earthquake, Nepal
I am involved in the GFZ HART project monitoring the ongoing effects of the Gorkha earthquake on surface processes. In particular, I am looking at landslide-channel coupling, the transport of coarse landslide material off of the hillslopes, and the effect of that material on the fluvial system.
Dynamics and impacts of glacial lake outburst floods
Our observatory in Nepal recorded the passage of a glacial lake outburst flood in July 2016, providing a unique set of data on GLOF propagation and impacts. We are combining seismic, suspended sediment, terrestrial lidar, and weather data with extensive field observations, time-lapse photographs, and remote sensing to explore GLOF dynamics and the role of such floods in fluvial erosion and landscape evolution.
Change detection using terrestrial lidar and UAV-based structure from motion
I use terrestrial lidar and small UAVs to obtain high resolution topography for monitoring geomorphic change in a range of settings. Applications include fluvial processes in the Daan River (UAV and lidar), hillslope and debris flow processes in the Illgraben (lidar), rockfall in the Reintal (lidar), landslide and hillslope change in Nepal (lidar), and cliff collapse on Rugen (UAV).
Cenozoic uplift, deformation, and landscape evolution in eastern Tibet
A number of projects are completed or underway on the eastern margin of the Tibetan Plateau. These include:
• Constraining Cenozoic deformation and uplift in the Danba region using low temperature thermochronology
• Mapping and dating multiple phases of granite emplacement in the Cenozoic Gongga granite to learn about the distribution of Cenozoic crustal melting and the timing of initiation of the Xianshuihe Fault
• Constraining the anomalous uplift of Gongga Shan and investigating its driving factors
• Distinguishing between the effects that variations in uplift and variations in lithology have on topographic metrics in the Yaan-Hanyuan region