Some features of the ASCE Shopping cart and login features of the website will be down for maintenance on Sunday, June 16th, 2024, beginning at 12:00 A.M. ET and ending at 6:00 A.M. ET. During this time if you need immediate assistance at 1-800-548-2723 or [email protected].

Chapter
Apr 26, 2012

The Role of Riparian Roots in Resisting the Hydraulic Scour of Streambanks

Publication: World Environmental and Water Resource Congress 2006: Examining the Confluence of Environmental and Water Concerns

Abstract

Riparian vegetation interacts in a number of ways with the geotechnical and hydraulic processes operating in streambanks. Previous research has shown that roots provide mechanical reinforcement to soil through the production of root-soil matrix, in which the roots resist tensile forces and strengthen banks against mass failure. In addition, plants have been shown to reduce pore-water pressures, and thus increase the stability of streambanks through removal of water by evapotranspiration. However, to date, very little has been documented about the effect of roots on hydraulic scour at bank toes, which when eroded, greatly increase bank instability. Quantification of the effects of riparian vegetation on streambank stability is important if we are to be able to design channel restoration projects that use biological strategies based on geomorphic effects as well as ecological and aesthetic benefits. In this study a vertical jet-test device was used to measure rates and volumes of scour in soils permeated by switchgrass roots. Twenty tests were carried out over a range of root densities. Root volume per unit volume of soil for the jet tests ranged from 0.0132 to 0.172 cm3<inf arrange="stagger">roots/cm3<inf arrange="stagger">soil. Erosion rates calculated for each jet-test showed stepped profiles for tests with roots (compared to smooth profiles for non root-permeated soils) because the roots protected the soil from erosion, initially at the surface and then at other points in the scour hole where roots were concentrated. Results show that the volume of soil scoured during a test declined non-linearly with increasing root volume, per unit volume of soil, and with increasing root length density (RLD) and increasing root biomass. The r2 for these relationships is fairly high despite the fact that root distributions relative to the shear stress field induced by the jet varied between tests, even under similar root volumes. The shape of the non-linearly declining functions between scoured soil volume and root biomass/root length density/root volume, suggest that a threshold exists at a relatively low root volume or biomass, above which, scour-hole volume was very small.

Get full access to this chapter

View all available purchase options and get full access to this chapter.

Information & Authors

Information

Published In

Go to World Environmental and Water Resource Congress 2006
World Environmental and Water Resource Congress 2006: Examining the Confluence of Environmental and Water Concerns
Pages: 1 - 10

History

Published online: Apr 26, 2012

Permissions

Request permissions for this article.

ASCE Technical Topics:

Authors

Affiliations

Watershed Physical Processes Research Unit, USDA-ARS National Sedimentation Laboratory, P.O. Box 1157, Oxford, MS 38655;. E-mail: [email protected]
Watershed Physical Processes Research Unit, USDA-ARS National Sedimentation Laboratory, P.O. Box 1157, Oxford, MS 38655. E-mail: [email protected]

Metrics & Citations

Metrics

Citations

Download citation

If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.

Cited by

View Options

Get Access

Access content

Please select your options to get access

Log in/Register Log in via your institution (Shibboleth)
ASCE Members: Please log in to see member pricing

Purchase

Save for later Information on ASCE Library Cards
ASCE Library Cards let you download journal articles, proceedings papers, and available book chapters across the entire ASCE Library platform. ASCE Library Cards remain active for 24 months or until all downloads are used. Note: This content will be debited as one download at time of checkout.

Terms of Use: ASCE Library Cards are for individual, personal use only. Reselling, republishing, or forwarding the materials to libraries or reading rooms is prohibited.
ASCE Library Card (5 downloads)
$105.00
Add to cart
ASCE Library Card (20 downloads)
$280.00
Add to cart
Buy Single Paper
$35.00
Add to cart

Get Access

Access content

Please select your options to get access

Log in/Register Log in via your institution (Shibboleth)
ASCE Members: Please log in to see member pricing

Purchase

Save for later Information on ASCE Library Cards
ASCE Library Cards let you download journal articles, proceedings papers, and available book chapters across the entire ASCE Library platform. ASCE Library Cards remain active for 24 months or until all downloads are used. Note: This content will be debited as one download at time of checkout.

Terms of Use: ASCE Library Cards are for individual, personal use only. Reselling, republishing, or forwarding the materials to libraries or reading rooms is prohibited.
ASCE Library Card (5 downloads)
$105.00
Add to cart
ASCE Library Card (20 downloads)
$280.00
Add to cart
Buy Single Paper
$35.00
Add to cart

Media

Figures

Other

Tables

Share

Share

Copy the content Link

Share with email

Email a colleague

Share