Physical and Biological Effects on Tide Flat Sediment Stability and Strength

Abstract

The ultimate goal of this research is to better understand the physical and biological processes that control the erosion, transport and deposition of fine-grained sediment in marine environments by collecting high-resolution field data that is compared to simple models. This research is part of the Tidal Flats Department Research Initiative (DRI) that is focused on understanding the controls of sediment strength over multiple time and space scales on the mud flats of Willapa Bay, Washington. My role in the DRI is to: (1) obtain high-resolution profiles of sediment bulk density to compare against erodibility measured by other investigators, and (2) collect data on surficial particulate organic carbon content and chlorophyll-a concentration. The latter are both proxies of exopolymeric substances (EPS), which are known to affect sediment erodibility. Our approach in the DRI has been to exploit the strong seasonality in physical forcing that exists on the Willapa Bay mud flats to better understand sediment erosion and deposition and the development of seabed strength. Thus, we have focused on making measurements during two parts of the year (March vs. July) that have important differences in key forcing variables (e.g., solar insolation, rainfall, wind waves, sea grass cover). Measurements have been mostly focused in and around a secondary, 5-m wide channel ("C-channel") that drains a portion of the Willapa Bay mud flat (Fig. 1). There, a series of stations have been occupied on the adjacent flats (B and C) and at various points across and along the channel itself.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2009
Accession Number
ADA527125

Entities

People

  • Robert A. Wheatcroft

Organizations

  • Oregon State University

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Aerial Photographs
  • Atmospheric Sciences
  • Biological Processes
  • Chlorophylls
  • Continental Shelves
  • Data Sets
  • Grain Size
  • High Resolution
  • Information Operations
  • Measurement
  • Photographs
  • Photography
  • Porosity
  • Rainfall
  • Seasonal Variations
  • Sediments
  • Universities

Readers

  • Geotechnical Engineering.
  • Marine Ecotoxicology
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers

Technology Areas

  • Space