Processes Controlling Transfer of Fine-Grained Sediment within and Between Channels and Flats on Intertidal Flats

摘要

A long-term goal of our sediment transport and accumulation investigations is to link sediment transport processes to the formation and preservation of event beds in sediment deposits. The general goal of this project is to investigate how forcing processes (e.g., tidal asymmetry, winds, river discharge and biological activity) affect the sediment-transport dynamics that act to import or export fine-grained sediment in intertidal regions. The resulting product is the formation of mud-flat environments with complex morphology (e.g., multiple scales of tidal channels, differing geotechnical and textural characteristic of flats). We investigate processes that transfer fine- grained sediment in intertidal settings between channels and flats and within channels, and relate them to the temporary and longer-term deposits found in those environments--how is the delicate balance of ebb and flood sediment fluxes maintained to create a relatively stable (or unstable) tidal flat complex. Specifically, we are trying to answer the question: What role do tidal (semidiurnal, fortnightly), riverine and other seasonal (winds/waves, temperature, and biological) processes have on the transfer of sediment between tidal-flat environments, and how is this manifested in terms of channel and flat deposits (temporary and longer-term).