An examination of controls on debris flow mobility: Evidence from coastal British Columbia

An examination of controls on debris flow mobility: Evidence from coastal British Columbia We characterize and consider controls to runout distance of debris slides and debris flows using 1700 field observations supplemented by air photograph interpretation from coastal British Columbia. We examine the role of slope on deposition and scour and determine that they occur on steeper and flatter slopes (respectively) than previously reported. Mean net deposition occurred on slopes between 18° and 24° for open slope failures and between 12° and 15° for channelized debris flows. We demonstrate a practical method for estimating both entrainment and runout in the field and in a GIS and provide an example entrainment map for Vancouver Island, British Columbia. We consider other controls to post failure landslide mobility, including the role of gullies and stream channels, roads and benches, and intact forests. Shallow landslides that hit streams and gullies at acute angles had a high probability of transforming into a channelized debris flow, whereas landslides that hit streams and gullies at obtuse angles did not. Forests played a substantial role in landslide runout: debris flows travelling through a logged slope deposited much of their load when hitting a forest boundary and stopped entirely within 50 m of that boundary in 72% of the cases examined. Roads also tended to stop or reduce the size of open slope debris flows in 52% of the cases. The results are expected to be useful to land management applications in regions with frequent shallow landsliding. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Geomorphology Elsevier

An examination of controls on debris flow mobility: Evidence from coastal British Columbia

Loading next page...
 
/lp/elsevier/an-examination-of-controls-on-debris-flow-mobility-evidence-from-t60OPEPSS7
Publisher
Elsevier
Copyright
Copyright © 2009 Elsevier Ltd
ISSN
0169-555X
eISSN
1872-695X
D.O.I.
10.1016/j.geomorph.2009.09.021
Publisher site
See Article on Publisher Site

Abstract

We characterize and consider controls to runout distance of debris slides and debris flows using 1700 field observations supplemented by air photograph interpretation from coastal British Columbia. We examine the role of slope on deposition and scour and determine that they occur on steeper and flatter slopes (respectively) than previously reported. Mean net deposition occurred on slopes between 18° and 24° for open slope failures and between 12° and 15° for channelized debris flows. We demonstrate a practical method for estimating both entrainment and runout in the field and in a GIS and provide an example entrainment map for Vancouver Island, British Columbia. We consider other controls to post failure landslide mobility, including the role of gullies and stream channels, roads and benches, and intact forests. Shallow landslides that hit streams and gullies at acute angles had a high probability of transforming into a channelized debris flow, whereas landslides that hit streams and gullies at obtuse angles did not. Forests played a substantial role in landslide runout: debris flows travelling through a logged slope deposited much of their load when hitting a forest boundary and stopped entirely within 50 m of that boundary in 72% of the cases examined. Roads also tended to stop or reduce the size of open slope debris flows in 52% of the cases. The results are expected to be useful to land management applications in regions with frequent shallow landsliding.

Journal

GeomorphologyElsevier

Published: Feb 1, 2010

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off