THRESHOLD BETWEEN MEANDERING AND BRAIDING.

Abstract

Geomorphologists and river engineers commonly accept that a river with a particular discharge regime will braid only if it flows on a gradient steeper than some critical threshold. This view is based particularly on the classic work of Leopold & Wolman (1957) on straight, meandering, and braided channel patterns. These authors emphasised that natural channel patterns intergrade, but their paper is remembered mainly for its demonstration that 'braided' rivers plot mostly above, and 'meandering' rivers mostly below, the threshold. Leopold & Wolman's concern was to explain why different rivers have different channel patterns at the present time, but their finding has implications for the prediction of channel pattern following engineering intervention in the controlling variables. Refs.