Measurements of the upward advection and pore-water profiles of salinity were made at three coastal settings (the Venice Lagoon, Italy; Jamaica Bay, New York; and Mattituck, New York). Coincident measurements of seepage rates using vented benthic chambers and profiles of salinity in pore water collected with a piezometer are used to quantify the coefficient of dispersive mixing. Three mathematical methods were used to quantify this coefficient: a simple, linearized salt balance and two analytical solutions to the steady-state, one-dimensional, advection-diffusion equation in either a slab or a semi-infinite medium. The majority of dispersive mixing coefficients in fine- to medium-grained silty sand were calculated to be between 0.04 and 0.8 m2 d-1. In some cases, the dispersive mixing seemed to involve small-scale preferred pathways for vertical transport, such as would be the case for bioirrigation, gravitational convection, or salt fingering.
The effect of groundwater advection on salinity in pore waters of permeable sediments
2009
Abstract
Measurements of the upward advection and pore-water profiles of salinity were made at three coastal settings (the Venice Lagoon, Italy; Jamaica Bay, New York; and Mattituck, New York). Coincident measurements of seepage rates using vented benthic chambers and profiles of salinity in pore water collected with a piezometer are used to quantify the coefficient of dispersive mixing. Three mathematical methods were used to quantify this coefficient: a simple, linearized salt balance and two analytical solutions to the steady-state, one-dimensional, advection-diffusion equation in either a slab or a semi-infinite medium. The majority of dispersive mixing coefficients in fine- to medium-grained silty sand were calculated to be between 0.04 and 0.8 m2 d-1. In some cases, the dispersive mixing seemed to involve small-scale preferred pathways for vertical transport, such as would be the case for bioirrigation, gravitational convection, or salt fingering.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
