The influence of large landslides on river incision in a transient landscape: Eastern margin of the Tibetan Plateau (Sichuan, China)

Abstract

Research Article| November 01, 2007 The influence of large landslides on river incision in a transient landscape: Eastern margin of the Tibetan Plateau (Sichuan, China) William B. Ouimet; William B. Ouimet 1Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Kelin X. Whipple; Kelin X. Whipple 2School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, USA Search for other works by this author on: GSW Google Scholar Leigh H. Royden; Leigh H. Royden 3Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Zhiming Sun; Zhiming Sun 4Chengdu Institute of Geology and Mineral Resources, Chengdu, Sichuan Province, China Search for other works by this author on: GSW Google Scholar Zhiliang Chen Zhiliang Chen 4Chengdu Institute of Geology and Mineral Resources, Chengdu, Sichuan Province, China Search for other works by this author on: GSW Google Scholar Author and Article Information William B. Ouimet 1Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Kelin X. Whipple 2School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, USA Leigh H. Royden 3Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Zhiming Sun 4Chengdu Institute of Geology and Mineral Resources, Chengdu, Sichuan Province, China Zhiliang Chen 4Chengdu Institute of Geology and Mineral Resources, Chengdu, Sichuan Province, China Publisher: Geological Society of America Received: 04 Nov 2006 Revision Received: 30 May 2007 Accepted: 07 Jun 2007 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 The Geological Society of America, Inc. GSA Bulletin (2007) 119 (11-12): 1462–1476. https://doi.org/10.1130/B26136.1 Article history Received: 04 Nov 2006 Revision Received: 30 May 2007 Accepted: 07 Jun 2007 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation William B. Ouimet, Kelin X. Whipple, Leigh H. Royden, Zhiming Sun, Zhiliang Chen; The influence of large landslides on river incision in a transient landscape: Eastern margin of the Tibetan Plateau (Sichuan, China). GSA Bulletin 2007;; 119 (11-12): 1462–1476. doi: https://doi.org/10.1130/B26136.1 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 SocietyGSA Bulletin Search Advanced Search Abstract Deep landscape dissection by the Dadu and Yalong rivers on the eastern margin of the Tibetan plateau has produced high-relief, narrow river gorges and threshold hillslopes that frequently experience large landslides. Large landslides inundate river valleys and overwhelm channels with large volumes (>105 m3) of coarse material, commonly forming stable landslide dams that trigger extensive and prolonged aggradation upstream. These observations suggest that strong feedbacks among hillslope processes, channel morphology, and incision rate are prevalent throughout this landscape and are likely characteristic of transient landscapes experiencing large increases in local relief, in general. Landslide effects are a by-product of rapid incision initiated by regional uplift. However, over timescales relevant to landscape evolution (>104 yr), large landslides can also act as a primary control on channel morphology and longitudinal river profiles, inhibiting incision and further preventing the complete adjustment of rivers to regional tectonic, climatic, and lithologic forcing.We explore a probabilistic, numerical model to provide a quantitative framework for evaluating how landslides influence bedrock river incision and landscape evolution. The time-average number of landslide dams along a river course, and thus the magnitude of the landslide influence, is set by two fundamental timescales—the time it takes to erode landslide deposits and erase individual dams and the recurrence interval of large landslides that lead to stable dams. Stable, gradually eroding landslide dams create mixed bedrock-alluvial channels with spatial and temporal variations in incision, ultimately slowing long-term rates of river incision, thereby reducing the total amount of incision occurring over a given length of river. A stronger landslide effect implies that a higher percentage of channel length is buried by landslide-related sediment, leading to reduced river incision efficiency. The longer it takes a river channel to incise into a landslide dam and remove all l