Comparative Study of Sediment Quality in Four Reservoirs

摘要

The distribution, accumulation, and quality of reservoir sediment is influenced by any number of factors, which include morphology, hydrology, preimpoundment conditions, and water quality. Sediment core samples were obtained from four U.S. Army Corps of Engineers reservoirs (Red Rock, DeGray, Eau Galle, and West Point Lakes) for the purpose of identifying the physical and chemical characteristics of their sediments. Sediment characteristics at Eau Galle Lake are greatly influenced by morphological conditions, while sediment characteristics at the other three reservoirs are dominated by hydrologic conditions. All four reservoir systems contain some local factors (e.g., tributaries, bridges) which cause deviations in expected sediment conditions. While these four reservoirs differ in size, shape, operation, and trophic condition, they all exhibit two distinguishable sedimentary zones: (1) a transport zone, which is dominated by turbulent processes (e.g., flow, wind) and characterized by a large median particle size; low moisture content; and low sediment nutrient, metal, and organic matter concentrations and (2) an accumulation zone, which is not affected by turbulence and is characterized as having a small median particle size; high moisture content; and high concentrations of sediment nutrients, metals, and organic matter.