Collaborative Research: Anabranching Channels in Jointed Bedrock: An Integrated Flume and Field Study

Colorado State University, Fort Collins CO

Investigators

Abstract

0228853 Wohl Our primary research objective is to quantitatively describe the interplay of the processes and rates of change in bedrock channels formed on jointed, resistant rock with particular reference to anabranching rivers. An anabranching river reach has multiple channels that branch and rejoin and are separated by surfaces that are dry or rarely flooded. We will use flume experiments and field studies of the Orange River in South Africa to explore the relationship of channel geometry developed on jointed, resistant rock to sediment discharge, lithology, tectonic regime, and joint spacing. The flume experiments and fieldwork will allow us to determine the conditions under which anabranching bedrock channels form and persist. Multiple substitutions of variables, accomplished by space substitution in the field and run design in the flume, will allow us to directly infer the relative influences of each variable. By conducting a systematic examination with experimental and field studies, we will increase our ability to establish cause and effect. This will benefit studies of bedrock rivers in general by directly contributing to the ability to parameterize bedrock channel processes, and ultimately the ability to model landscape evolution. Furthermore, we will use this project as an opportunity to train young scientists and to foster scientific and cultural exchange between South Africa and the United States. Graduate students will be integral parts of the research program and we will work collaboratively with colleagues in South Africa and from Wales. The graduate students will gain important scientific and cultural knowledge, we will gain valuable international experience, and our South African and Welsh colleagues will gain international exposure through our work.