No description available.

Sediment resuspension due to the operation of recreational motorboats in shallow lakes was investigated. Boats equipped with 28, 50, 85, 120, and 165 horsepower engines were used for this study on Lake Claire, Florida Technological University campus, and Lake Mizell, the City of Winter Park, located in Orange County, Central Florida. Grasshopper Lake was also a test site due to its clarity for underwater photography. These motorboats were run at different speeds and water depths and the induced pressure waves on the lake bottom were measured using a hydrophone and recording system. Primary and secondary wave amplitudes and frequencies were determined for the various operating conditions and motorboats. The primary waves were formed by boat wake and the secondary waves resulted from engine effects. The primary waves were generally higher in amplitude and lower in frequency than the secondary waves. The maximum amplitudes occurred just before planing. The average primary wave amplitude after planing at normal operating speeds decreased exponentially with increasing water depth for all the boats tested and followed this equation: Aw = ae-bD where: Aw = average primary wave amplitude, ft. a = constant varied between boats = 0.68 to 1.86 ft. for boats tested b = 0.17 to 0.25 ft-1 D = water depth, ft The boat waves resuspended bottom sediments and eroded shore areas, increasing the turbidity of the lake water. Particle count and size distribution in water samples were determined using a Coulter Counter. A straight line relationship between turbidity and cummulative particle count per milliliter existed on a semi-log graph. Calculated and measured bottom water velocities showed good agreement for a limited amount of data.

Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Bibliography: leaves 55-58. / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN / Bibliography: leaves 130-131. / by Robert Anthony Grazer. / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1981. / Microfiche copy available in Archives and Science. Film reel in Science Library. / Bibliography: leaves 79-80. / by Peter John Vrolijk. / M.S.

No description available.

Sedimentation (erosion, transport, and deposition) is a primary and growing environmental, engineering, and agricultural issue around the world. However, collection of the data needed to develop solutions to sedimentation issues has declined by about three-fourths since 1983. Suspended-sediment surrogates have the potential to obtain sediment data using methods that are more accurate, of higher spatial and temporal resolution, and with less manually intensive, costly, and hazardous methods. The improved quality of sediment data from high-resolution surrogates may inform improved understanding and solutions to environmental, engineering, and agricultural sedimentation problems. The field experiments for this research includ physical samples of suspended sediment collected concurrently with surrogate metrics from instruments including 1.2, 1.5, and 3.0 megahertz frequency acoustic doppler current profilers, a nephelometric turbidity sensor, and a laser-diffraction particle size analyzer. This comprehensive data set was collected over five storms in 2009 and 2010 at Yellow River near Atlanta, Georgia. This research project has proposed, developed, and tested a new method for evaluation of sediment size from theoretical acoustic attenuation; evaluated and further developed recently introduced empirical methods for estimating acoustic attenuation by sediment; found and quantified data mischaracterization issues for laser-diffraction metrics; defined deterministic causes for observed hysteresis and variance in suspended sediment to surrogate relations; compared the accuracy of sediment concentration models and loads for each tested surrogate; and compared sediment surrogate technologies on the basis of reliability and operational considerations.

Thesis (Ph. D.)--University of Washington, 2002. / Includes bibliographical references (leaves 240-251).

No description available.

Hazelmere Dam situated on the Mdloti River in KwaZulu-Natal has, since its completion in 1977, lost 25 % of its original design capacity through sedimentation. This storage loss has brought about an environmental concern as well as a socio -economic threat to the region. The aim of this research was to investigate the effect of land use change on the sedimentation rate in the catchment. This was undertaken to obtain a better understanding of the processes and leads towards an integrated catchment management strategy. Geographical information systems afforded the opportunity to determine land use change from a number of sequential land use maps and to run statistical analyses and overlays. It was determined that a large change in land use had taken place between subsistence cultivation/small-scale agriculture and subsistence grazing. The rainfall, soil and slope conditions cause the catchment to have a naturally high erosion potential. As a result of the interrelated nature of all these factors in the catchment the most effective manner in which to deal with the sedimentation problem is through a multidisciplinary approach such as is afforded by integrated catchment management strategies. In terms of controlling the sedimentation problem in the Hazelmere Dam recommendations concerning conservation practices necessary in minimising the impact of the land use practices and changes are made for inclusion in such a management approach. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.