The influence of coarse woody debris on gravel beach geomorphology

Abstract

Coarse woody debris (CWD) is an important component of fluvial systems affecting in-channel hydrology and sediment storage which in turn controls channel geometry and evolution. The role of coarse woody debris in coastal geomorphology is an emerging research field and this study investigates its role on mixed sand and gravel beach systems. A case-study approach is used whereby two field areas in Wellington, New Zealand, each with two distinct beaches with differing wood accumulations, were investigated through field surveying. It is found that on gravel beaches CWD is most important during storm events where it causes the berm crests to be 0.5-1.0. m higher than on unwooded beaches, as well ..