EAPSI: Evaluating the Geologic History and Impact of River Blockages Caused by Landslides in Taiwan

Belliveau Lindsey C, Amston CT

Investigators

Abstract

Taiwan commonly annually experiences significant natural disasters including typhoons and earthquakes that can trigger massive landslides. When landslides fall into rivers they form dams that block flow and lead to sediment deposition that gets preserved in the river valleys. These sediments can be measured and dated to gain an overall understanding of Taiwan?s tectonic and climatic history as they are both responsible for triggering landslides. Better understanding this behavior can assist in preparing for future events, including the geohazards brought forth from these dams that affect the safety of people who live in mountainous areas (such as the tragic 2009 Xiaolin Dam failure). This research will be conducted using high quality satellite imagery that is only available in Taiwan and other computerized data processing techniques as well as field studies. This project will be conducted at Academia Sinica?s Institute of Earth Sciences in Taipei, Taiwan under the mentorship of Dr. Yu-Chang Chan. This collaboration provides an opportunity to have access to unique data that will enable new understanding of landslide impacts in Taiwan and address their role in changing the physical landscape. Taiwan is one of the most rapidly eroding and tectonically active regions in the world, allowing it to be the ultimate natural experiment for research in tectonic geomorphology (landscape evolution). Landslides are a widespread feature of erosion in Taiwan, with direct connection to tectonic and climatic processes. Dramatic landslide events associated with large earthquakes and typhoons, as well as the increase in sediment transport and deposition that result from them, highlight the role the landslides play in pacing and shaping landscape evolution in Taiwan. Few studies, however, have addressed the longer-term geomorphic record of past landslides events throughout the region on a national scale and few have specifically investigated the further-reaching roles that landslide dams have played. Landslide dams have been studied in mountainous regions around the world and have shown the long-term effects on river incision and landscape evolution. This project will document and study the diverse record of paleo-landslides dams in Taiwan attesting to their marks left in the landscape?s evolution, as well as controls on their spatial variation such as proximity to active faults, lithology, and historic typhoon density. This NSF EAPSI award is funded in collaboration with the Ministry of Science and Technology of Taiwan.