Compensational behavior of three debris-flow fans in southern Colorado
dc.contributor.advisor | Santi, Paul M. (Paul Michael), 1964- | |
dc.contributor.advisor | Pyles, David R. | |
dc.contributor.author | Pederson, Chris Andrew | |
dc.date.accessioned | 2007-01-03T06:31:06Z | |
dc.date.accessioned | 2022-02-09T08:56:14Z | |
dc.date.available | 2007-01-03T06:31:06Z | |
dc.date.available | 2022-02-09T08:56:14Z | |
dc.date.issued | 2014 | |
dc.date.submitted | 2014 | |
dc.identifier | T 7557 | |
dc.identifier.uri | https://hdl.handle.net/11124/472 | |
dc.description | 2014 Spring. | |
dc.description | Includes illustrations (some color), color maps. | |
dc.description | Includes bibliographical references (pages 45-46). | |
dc.description.abstract | Building an understanding of debris-flow avulsion tendencies would deepen the understanding of sediment transport modes and inform hazard assessment and mitigation by suggesting the paths of future debris-flows following channel avulsion. To explore these tendencies, three debris fans were selected in southern Colorado for compensational analysis. Compensation refers to the tendency of discrete flow events to preferentially fill topographic lows following channel avulsions (Straub et al., 2009). By assessing the level of compensational behavior within each fan, it was possible to predict, in a general sense, the avulsion tendency. To assess the level of compensation present within each fan, outcrops where either natural or anthropogenic processes had acted to expose strata were located and subdivided into discrete depositional units. The relative size and positioning of each unit was used in a statistical analysis of compensation within each debris fan system. The result of this analysis was a single number, referred to as the modified compensation index (Straub and Pyles, 2012), for each outcrop which varied from 0.63 to 1.03 across the three exposures. Values close to 0.5 represent intermediate avulsion tendencies within a fan, while results approaching 1.0 reflect more compensational behavior. Values less than 0.5 correspond to anti-compensational, or aggradational behavior which is rarely observed in nature (Straub and Pyles, 2012). The results of this project include a correlation assessment of modified compensation indices versus other data collected in the field and interpreted in the lab including: the percent stream flow material by area, percent clay by mass in the matrix, percent by volume of pebble-sized clasts, percent by volume of cobble-sized and greater clasts, maximum observed unit thickness, observed unit width, unit width-to-thickness ratio, fractional outcrop distance from the fan apex, and absolute distance of outcrop from the fan apex. It is intended that engineers and developers may predict the level of compensation and therefore the avulsion habits of a debris fan by observing a combination of these readily measurable parameters. As a result, mitigation methods could be selected and arranged more strategically to account for the likely direction of debris-flow avulsions in the future. | |
dc.format.medium | born digital | |
dc.format.medium | masters theses | |
dc.language | English | |
dc.language.iso | eng | |
dc.publisher | Colorado School of Mines. Arthur Lakes Library | |
dc.relation.ispartof | 2010-2019 - Mines Theses & Dissertations | |
dc.rights | Copyright of the original work is retained by the author. | |
dc.subject | hazard | |
dc.subject | fan | |
dc.subject | avulsion | |
dc.subject | debris-flow | |
dc.subject | compensation | |
dc.subject.lcsh | Debris avalanches -- Colorado | |
dc.subject.lcsh | Alluvial fans -- Colorado | |
dc.subject.lcsh | Sediment transport | |
dc.subject.lcsh | Correlation (Statistics) | |
dc.subject.lcsh | Hazard mitigation | |
dc.title | Compensational behavior of three debris-flow fans in southern Colorado | |
dc.type | Text | |
dc.contributor.committeemember | Zhou, Wendy | |
dc.contributor.committeemember | Higgins, Jerry D. | |
thesis.degree.name | Master of Science (M.S.) | |
thesis.degree.level | Masters | |
thesis.degree.discipline | Geology and Geological Engineering | |
thesis.degree.grantor | Colorado School of Mines |