13 Sep 2022

Sediment Mobility, Closure Depth, and the Littoral System – Oregon and Washington Coast

Abstract: Forty years ago, the depth of closure concept was introduced to provide a systematic, process-based approach to evaluate seasonal changes in cross-shore profiles and sediment mobility in the nearshore. This study aims to extend that theory by directly considering wave-asymmetry in the nearshore environment. This technical note introduces a methodology to calculate wave induced dispersal of dredged material placed in nearshore sites and summarizes analyses validating the approach using data from the South Jetty Site at the Mouth of the Columbia River. This investigation highlights the notion of a cross-shore gradient in nearshore placement effectiveness of dredged material that can assist project managers plan and execute sustainable sediment management practices at coastal inlets.