Project Number: 6408-13000-020-01
Project Type: Specific Cooperative Agreement

Start Date: Sep 01, 2007
End Date: Aug 31, 2012

Objective:
Objectives are directed toward the development and evaluation of innovative acoustic and seismic measurement techniques for monitoring sediment transport processes in fluvial environments, sediment accumulation in impoundment reservoirs, and the structural integrity of earthen dams. The proposed research objectives are: (1) development of measurement and monitoring technologies for determining the temporal and spatial distribution, variation, and evolution of both suspended and bedload sediments in fluvial environments; (2) initiate field and laboratory studies using acoustic technologies for spatial delineation and characterization of sediments in relatively shallow reservoirs upstream from flood control dams; and (3) develop acoustic and/or seismic methodologies for identifying piping failure or changes in the structural integrity of earthen dams.

Approach:
(1) Advance the state-of-the-art in the use of multiple acoustic frequencies for extracting detailed concentration and particle-size distribution information using laboratory tests. Deploy low cost acoustic systems in stream cross sections, and investigate the use of passive acoustic techniques to characterize bedload transport through passive measurements of gravel and sand dune migration. (2) Characterize the relationships between acoustic attributes, such as acoustic velocity, absorption, and impedance of sediments, and sediment physical properties, such as bulk density, grain size distribution, and pore fluid concentrations and study the relevant physical properties of the impoundment sediments and their relationship to acoustic attributes based on laboratory experiments. Develop the use of high-resolution acoustic sub-bottom profiling systems for sediment delineation and characterization by developing complementary acoustic field techniques of mapping and characterizing sediment accumulations in small flood-control reservoirs. (3) Study and evaluate the usefulness of seismic and acoustic techniques (e.g. seismic refraction tomography) for delineating the internal structure of earthen dams.