Landslide-driven drainage divide migration

Abstract

Research Article| February 23, 2018 Landslide-driven drainage divide migration Maxwell P. Dahlquist; Maxwell P. Dahlquist 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar A. Joshua West; A. Joshua West 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar Gen Li Gen Li 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Maxwell P. Dahlquist 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA A. Joshua West 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Gen Li 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Publisher: Geological Society of America Received: 19 May 2017 Revision Received: 20 Nov 2017 Accepted: 05 Feb 2018 First Online: 23 Feb 2018 Online Issn: 1943-2682 Print Issn: 0091-7613 © 2018 Geological Society of America Geology (2018) 46 (5): 403–406. https://doi.org/10.1130/G39916.1 Article history Received: 19 May 2017 Revision Received: 20 Nov 2017 Accepted: 05 Feb 2018 First Online: 23 Feb 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Maxwell P. Dahlquist, A. Joshua West, Gen Li; Landslide-driven drainage divide migration. Geology 2018;; 46 (5): 403–406. doi: https://doi.org/10.1130/G39916.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Drainage divide migration reorganizes river basins, redistributing erosive energy and contributing to feedbacks between tectonics, erosion, and climate. However, the conditions governing divide migration and the time scales on which it occurs are poorly understood. By connecting channels to hillslopes in steep landscapes, landslides are expected to play a central role in divide migration and landscape evolution. In this study, we examine landslides triggered by three events (two earthquakes and a tropical cyclone), seeking insight into controls on divide migration. Of the ∼100,000 landslides triggered, we mapped 365 that caused a divide to migrate, resulting in a total exchange of ∼2 km2 between basins from ∼82,000 km2 affected by landsliding. By applying several proposed metrics for divide stability based on river channel morphology, we use our database of divide migrations to test for the role of landslides in coupling between channels and divides. We find that, at the time scale of a single landslide-generating event, patterns of area gain and loss between basins are consistent with landscapes progressing toward steady state, as inferred from channel metrics. We also propose a metric to quantify divide migration, area exchange, and the contribution of an event toward topographic steady state. Restricting our analysis to the main drainage divide, and using estimates of recurrence interval and the rate of topographic evolution in Taiwan, we calculate that landslides triggered by large typhoons account for a minimum of 12%–15% of southern Taiwan’s progress toward steady state. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.