Geography Publications

Document Type

Article

Publication Date

2017

Volume

65

Journal

Sedimentology

First Page

877

Last Page

896

URL with Digital Object Identifier

https://doi.org/10.1111/sed.12409

Abstract

A Froude‐scaled physical model of a proximal gravel‐bed braided river was used to connect the river morphological characteristics, and sedimentary processes and forms, to deposit geometry. High resolution continuous three‐dimensional topographic data were acquired from sequential photogrammetric digital elevation models paired with grain‐size surface maps derived from image analysis of textural properties of the surface. From these data, the full three‐dimensional development of the braided river deposit and grain‐size sorting patterns was compiled over an experimental time period of 41 h during which the model river reworked a large portion of the braided channel. The minimum surface of the deposit is developed progressively over time by erosion, migration and avulsion of channels, and by local scour at channel confluences. The maximum surface of the deposit is formed by amalgamation of braid bar surfaces and has less overall relief than the minimum surface. Confluence scour constitutes about 5% of the area of the minimum surface. Migration of individual confluences is limited to distances of the order of the width and length of the confluence, so that confluences do not form laterally extensive deposits and basal surfaces. Maximum and minimum surfaces have very similar grain‐size distributions, and there is no extensive basal coarse layer. Deposit maximum thickness is strongly associated with large channel confluences which occur as deeper areas along the main channel belt and make up a large proportion of the thickest portions of the deposit.

Notes

This is the peer reviewed version of the following article: Morpho-sedimentary characteristics of proximal gravel braided river deposits in a Froude-scaled physical model in Sedimentology Vol. 65, which has been published in final form at https://doi.org/10.1111/sed.12409. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

Find in your library

Share

COinS