CaltechAUTHORS
  A Caltech Library Service

Numerical simulations of bedrock valley evolution by meandering rivers with variable bank material

Limaye, Ajay B. S. and Lamb, Michael P. (2014) Numerical simulations of bedrock valley evolution by meandering rivers with variable bank material. Journal of Geophysical Research. Earth Surface, 119 (4). pp. 927-950. ISSN 2169-9003. http://resolver.caltech.edu/CaltechAUTHORS:20140619-085726107

[img]
Preview
PDF - Published Version
See Usage Policy.

8Mb
[img] Plain Text (Readme) - Supplemental Material
See Usage Policy.

1902b
[img] Video (MPEG) (Movie S1) - Supplemental Material
See Usage Policy.

2486Kb
[img] Video (MPEG) (Movie S2) - Supplemental Material
See Usage Policy.

3163Kb
[img] Video (MPEG) (Movie S3) - Supplemental Material
See Usage Policy.

5Mb
[img] Video (MPEG) (Movie S4) - Supplemental Material
See Usage Policy.

3381Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20140619-085726107

Abstract

Bedrock river valleys are fundamental components of many landscapes, and their morphologies—from slot canyons with incised meanders to wide valleys with strath terraces—may record environmental history. Several formation mechanisms for particular valley types have been proposed that involve changes in climatic and tectonic forcing, but the uniqueness of valley evolution pathways and the long-term stability of valley morphology under constant forcing are unknown and are not predicted in existing numerical models for vertically incising rivers. Because rivers often migrate more rapidly through alluvium than through bedrock, we explore the hypothesis that the distribution of bank materials strongly influences river meandering kinematics and can explain the diversity of bedrock river valley morphology. Simulations using a numerical model of river meandering with vector-based bank-material tracking indicate that channel lateral erosion rate in sediment and bedrock, vertical erosion rate, and initial alluvial-belt width explain first-order differences in bedrock valley type; that bedrock-bound channels can evolve under steady forcing from alluvial states; and that weak bedrock and low vertical incision rates favor wide, shallow valleys, while resistant bedrock and high vertical incision rates favor narrow, deep valleys. During vertical incision, sustained planation of the valley floor is favored when bedrock boundaries restrict channel migration to a zone of thin sediment fill. The inherent unsteadiness of river meandering in space and time is enhanced by evolving spatial contrasts in bank strength between sediment and bedrock and can account for several valley features—including strath terraces and underfit valleys—commonly ascribed to external drivers.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1002/2013JF002997 DOIArticle
http://onlinelibrary.wiley.com/doi/10.1002/2013JF002997/abstractPublisherArticle
http://onlinelibrary.wiley.com/doi/10.1002/2013JF002997/suppinfoPublisherSupporting Information
ORCID:
AuthorORCID
Lamb, Michael P.0000-0002-5701-0504
Additional Information:© 2014 American Geophysical Union. Received 30 SEP 2013; Accepted 3 APR 2014; Accepted article online 6 APR 2014; Published online 29 APR 2014. This work was supported by the Department of Defense through the National Defense Science and Engineering Graduate Fellowship (NDSEG) Program and NSF grant EAR-1147381 to MPL. Acknowledgment is also made to the Donors of the American Chemical Society Petroleum Research Fund for partial support of this research. We thank Jean-Philippe Avouac, Noah Finnegan, Alan Howard, Bob Anderson, Brian Yanites, and Associate Editor Dimitri Lague for helpful comments.
Funders:
Funding AgencyGrant Number
Department of Defense (DOD) UNSPECIFIED
National Defense Science and Engineering Graduate (NDSEG) FellowshipUNSPECIFIED
NSFEAR-1147381
American Chemical Society Petroleum Research FundUNSPECIFIED
Subject Keywords:bedrock river valleys; meandering; bank strength; landscape evolution
Record Number:CaltechAUTHORS:20140619-085726107
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20140619-085726107
Official Citation:Limaye, A. B. S., and M. P. Lamb (2014), Numerical simulations of bedrock valley evolution by meandering rivers with variable bank material, J. Geophys. Res. Earth Surf., 119, 927–950, doi:10.1002/2013JF002997
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:46351
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:19 Jun 2014 19:12
Last Modified:23 Nov 2016 00:50

Repository Staff Only: item control page