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Measuring groundwater transport through lake sediments by advection and diffusion
Author(s) -
Cornett R. J.,
Risto B. A.,
Lee D. R.
Publication year - 1989
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr025i008p01815
Subject(s) - advection , groundwater , groundwater flow , geology , inflow , sediment , outflow , hydrology (agriculture) , diffusion , pore water pressure , environmental science , soil science , aquifer , geomorphology , geotechnical engineering , oceanography , physics , thermodynamics
A method for estimating low rates of groundwater inflow and outflow through the bottom sediments of surface waters was developed and tested. A one‐dimensional advection‐diffusion model was fitted to measured pore water profiles of two nonreactive solutes, tritiated water and chloride, and the advection rate was calculated by a nonlinear least squares technique. Using 3 H profiles measured 0–0.5 m below the sediment‐water interface, rates of groundwater advection into a lake through interbedded sands and gyttja were estimated to be about 1.0 m/year. In midlake locations underlain by soft organic gyttja, rates of advection were much lower (<0.1 m/year). Knowledge of the rate and direction of groundwater flow substantially altered the interpretation of pore water profiles within the sediments and the fluxes of solutes. This technique can be used to estimate flow rates less than 2 m/annum with minimal disturbance, without enclosing the sediments in a container, in a diversity of systems.