Year: 2005
Type: article
Abstract: Investigations using a 16 m by 2 m recirculating experimental flume model of an ephemeral braided river indicate that the presence of large and erosion‐resistant plants within the channel (e.g., trees or shrubs) can have a significant impact on channel pattern and planform dynamics. Simulations show that these plants have two effects. First, they act as obstructions, in some cases forcing the flow to divide. This flow separation can allow the deposition of a small island immediately in the lee of the plant splitting the channel. The net result is a substantial increase in the number of channels and, correspondingly, the braid index. This is in direct contrast to previous studies, where increased levels of vegetation in perennial streams have decreased the braid index. Second, the plants stabilize braid bars and can form relatively stable islands in their lee, significantly reducing the longitudinal migration of islands typically associated with braided rivers.
Source: Water Resources Research
DOI: 10.1029/2004wr003201
Author: Tom J. Coulthard
Institutions: Aberystwyth University, University of Wales
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1611960773