Objective delineation of lahar-inundation hazard zones

Research Article| August 01, 1998 Objective delineation of lahar-inundation hazard zones Richard M. Iverson; Richard M. Iverson 1U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Search for other works by this author on: GSW Google Scholar Steven P. Schilling; Steven P. Schilling 1U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Search for other works by this author on: GSW Google Scholar James W. Vallance James W. Vallance 2Department of Civil Engineering and Applied Mechanics, McGill University, Montreal, Quebec H3A 2K6, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Richard M. Iverson 1U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Steven P. Schilling 1U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 James W. Vallance 2Department of Civil Engineering and Applied Mechanics, McGill University, Montreal, Quebec H3A 2K6, Canada Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1998) 110 (8): 972–984. https://doi.org/10.1130/0016-7606(1998)110<0972:ODOLIH>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Richard M. Iverson, Steven P. Schilling, James W. Vallance; Objective delineation of lahar-inundation hazard zones. GSA Bulletin 1998;; 110 (8): 972–984. doi: https://doi.org/10.1130/0016-7606(1998)110<0972:ODOLIH>2.3.CO;2 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 A new method of delineating lahar hazard zones in valleys that head on volcano flanks provides a rapid, objective, reproducible alternative to traditional methods. The rationale for the method derives from scaling analyses of generic lahar paths and statistical analyses of 27 lahar paths documented at nine volcanoes. Together these analyses yield semiempirical equations that predict inundated valley cross-sectional areas (A) and planimetric areas (B) as functions of lahar volume (V). The predictive equations (A = 0.05V2/3 and B = 200 V2/3) provide all information necessary to calculate and plot inundation limits on topographic maps. By using a range of prospective lahar volumes to evaluate A and B, a range of inundation limits can be plotted for lahars of increasing volume and decreasing probability. Resulting hazard maps show graphically that lahar-inundation potentials are highest near volcanoes and along valley thalwegs, and diminish gradually as distances from volcanoes and elevations above valley floors increase. We automate hazard-zone delineation by embedding the predictive equations in a geographic information system (GIS) computer program that uses digital elevation models of topography. Lahar hazard zones computed for Mount Rainier, Washington, mimic those constructed on the basis of intensive field investigations. The computed hazard zones illustrate the potentially widespread impact of large lahars, which on average inundate planimetric areas 20 times larger than those inundated by rock avalanches of comparable volume. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.