Synthesis of benthic flux components in the Patos Lagoon coastal zone, Rio Grande do Sul, Brazil

Authors


Corresponding author: J. N. King, U. S. Geological Survey Florida Water Science Center, 7500 S.W. 36th St., Davie, FL 33314, USA. (jking@usgs.gov)

Abstract

[1] The primary objective of this work is to synthesize components of benthic flux in the Patos Lagoon coastal zone, Rio Grande do Sul, Brazil. Specifically, the component of benthic discharge flux forced by the terrestrial hydraulic gradient is 0.8 m3 d−1; components of benthic discharge and recharge flux associated with the groundwater tidal prism are both 2.1 m3 d−1; components of benthic discharge and recharge flux forced by surface-gravity wave setup are both 6.3 m3 d−1; the component of benthic discharge flux that transports radium-228 is 350 m3 d−1; and components of benthic discharge and recharge flux forced by surface-gravity waves propagating over a porous medium are both 1400 m3 d−1. (All models are normalized per meter shoreline.) Benthic flux is a function of components forced by individual mechanisms and nonlinear interactions that exist between components. Constructive and destructive interference may enhance or diminish the contribution of benthic flux components. It may not be possible to model benthic flux by summing component magnitudes. Geochemical tracer techniques may not accurately model benthic discharge flux or submarine groundwater discharge (SGD). A conceptual model provides a framework on which to quantitatively characterize benthic discharge flux and SGD with a multifaceted approach.

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