Supply and dispersal of flood sediment from a steep, tropical watershed: Hanalei Bay, Kaua’i, Hawai’i, USA

Research Article| March 01, 2009 Supply and dispersal of flood sediment from a steep, tropical watershed: Hanalei Bay, Kaua'i, Hawai'i, USA A.E. Draut; A.E. Draut † 1U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA †E-mail: adraut@usgs.gov Search for other works by this author on: GSW Google Scholar M.H. Bothner; M.H. Bothner 2U.S. Geological Survey, 384 Woods Hole Road, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar M.E. Field; M.E. Field 3U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA Search for other works by this author on: GSW Google Scholar R.L. Reynolds; R.L. Reynolds 4U.S. Geological Survey, Mail Stop 980, Denver Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar S.A. Cochran; S.A. Cochran 5U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA Search for other works by this author on: GSW Google Scholar J.B. Logan; J.B. Logan 5U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA Search for other works by this author on: GSW Google Scholar C.D. Storlazzi; C.D. Storlazzi 5U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA Search for other works by this author on: GSW Google Scholar C.J. Berg C.J. Berg 6Hanalei Watershed Hui, P.O. Box 1285, Hanalei, Hawai'i 96714, USA Search for other works by this author on: GSW Google Scholar Author and Article Information A.E. Draut † 1U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA M.H. Bothner 2U.S. Geological Survey, 384 Woods Hole Road, Woods Hole, Massachusetts 02543, USA M.E. Field 3U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA R.L. Reynolds 4U.S. Geological Survey, Mail Stop 980, Denver Federal Center, Denver, Colorado 80225, USA S.A. Cochran 5U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA J.B. Logan 5U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA C.D. Storlazzi 5U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA C.J. Berg 6Hanalei Watershed Hui, P.O. Box 1285, Hanalei, Hawai'i 96714, USA †E-mail: adraut@usgs.gov Publisher: Geological Society of America Received: 13 Nov 2007 Revision Received: 18 Apr 2008 Accepted: 25 Jul 2008 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2009 Geological Society of America GSA Bulletin (2009) 121 (3-4): 574–585. https://doi.org/10.1130/B26367.1 Article history Received: 13 Nov 2007 Revision Received: 18 Apr 2008 Accepted: 25 Jul 2008 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation A.E. Draut, M.H. Bothner, M.E. Field, R.L. Reynolds, S.A. Cochran, J.B. Logan, C.D. Storlazzi, C.J. Berg; Supply and dispersal of flood sediment from a steep, tropical watershed: Hanalei Bay, Kaua'i, Hawai'i, USA. GSA Bulletin 2009;; 121 (3-4): 574–585. doi: https://doi.org/10.1130/B26367.1 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 In contrast to many small, mountainous watersheds in temperate coastal regions, where fluvial discharge and wave energy commonly coincide, deposition and reworking of tropical flood sediment can be seasonally decoupled, and this has important implications for coral-reef ecosystems. An understanding of the interaction between tropical flood sedimentation and wave climate is essential to identifying and mitigating effects of watershed changes on coral reefs as urbanization and climate change proceed. Sedimentary facies and isotopic properties of sediment in Hanalei Bay, on the island of Kaua'i, Hawai'i, USA, were used to assess deposition and reworking of flood deposits from the Hanalei River in a case study demonstrating the potential ecosystem effects of runoff from a steep, tropical watershed.In Hanalei Bay, the youngest and thickest terrigenous sediment was consistently present near the river mouth and in a bathymetric depression that acted as at least a temporary sediment sink. During this 2 yr study, the largest flood events occurred in late winter and spring 2006; substantial terrestrial sediment delivered by those floods still remained in the bay as of June 2006 because oceanic conditions were not sufficiently energetic to transport all of the sediment offshore. Additional sediment was deposited in the bay by a summer 2006 flood that coincided with seasonal low wave energy. In most years, flood sediment accumulating in the bay and on its fringing reefs would be remobilized and advected out of the bay during winter, when the wave climate is energetic. Turbidity and sedimentation on corals resulting from late spring and summer floods during low wave energy could have a greater impact on coral-reef ecosystems than floods in other seasons, an effect that could be exacerbated if the incidence and sediment load of tropical summer floods increase due to urbanization and climate change. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.