AN EXPERIMENTAL STUDY OF FINE-PARTICLE DEPOSITION TO PERMEABLE STATIONARY AND WEAKLY-MOBILE SAND BEDS UNDERLYING TURBULENT FLOWS

Dartmouth College, Hanover NH

Investigators

Abstract

This project will investigate the rates at which fine particles are delivered to, and penetrate into, streambeds. Fine-particle deposition affects streambed permeability, and thus directly impacts such processes as the sequestration of sediment and contaminants in fluvial environments, microbially-constrained aspects of geochemical cycles and larval recruitment at the sediment-water interface. A detailed understanding of fine-particle deposition will (i) improve boundary conditions for regional models of sediment and contaminant transport and fate, and (ii) improve understanding of physical factors that constrain benthic biogeochemical processes and related benthic biocomplexity. The PIs propose to determine the degree to which weak bedload transport of a coarse granular bed affects rates of deposition of silt-sized particles from dilute, turbulent suspension. The proposed research will be conducted in a new flume now under construction with expected completion by Summer 2004.