HR: 15:45h
AN: H14A-02    [Abstracts]
TI: The Potential Impact of Coupled Physical and Chemical Processes on the Retention Efficiency of Ponds
AU: * Branco, B
EM: brett.branco@uconn.edu
AF: University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT 06340 United States
AU: Torgersen, T
EM: thomas.torgersen@uconn.edu
AF: University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT 06340 United States
AB: Ponds can attenuate the concentration of nutrients, metals and other pollutants in storm water through particle settling and biological uptake. However, the percent removal of a particular constituent varies widely over multiple ponds and storm events. In some cases ponds can export more of a constituent than they import (negative retention). The factors that effect the retention efficiency of ponds are not well documented. The retention efficiency may be affected by the coupled physical and biogeochemical dynamics in ponds between storm events. During quiescent periods, ponds may undergo a diel thermal stratification/destratification cycle. The night time destratification is not always complete and residual density gradients can remain. The magnitude and persistence of the stratification is strongly affected by the geometry of the pond, the diffuse attenuation coefficients for shortwave radiation and the dominant primary producer type (phytoplankton or macrophytes). High spatial and temporal resolution measurements in two shallow, eutrophic ponds in Storrs, Connecticut demonstrate that chemical stratification is closely linked to the diel thermal stratification cycle and the dominant primary producer type. A 3-dimensional hydrodynamic model and a 1-dimensional biogeochemical model are used to evaluate the impacts of mixing frequency and the coupled physical and biogeochemical processes on internal nutrient and iron loading in shallow aquatic systems.
DE: 1806 Chemistry of fresh water
DE: 1845 Limnology
DE: 1871 Surface water quality
DE: 4568 Turbulence, diffusion, and mixing processes
DE: 4842 Modeling
SC: Hydrology [H]
MN: 2005 Joint Assembly