Calibration and Verification of a Hydrodynamic Model for a Narrow Estuary Receiving Submarine Groundwater Discharges

Abstract

This paper presents calibration and verification of the laterally averaged model for estuaries (LAMFE) for the Chassahowitzka River, a spring-fed estuary located on the Gulf coast of central Florida, USA. The river is a narrow and complex riverine system that receives submarine groundwater discharges (SGDs), which are difficult to measure. This study tried to make a reasonable estimate of some unquantified or missing SGD data with a trial-and-error approach in the model calibration process. The model was successfully calibrated against measured real-time data of water level, salinity, and temperature at three locations within the simulation domain from November 2012 to December 2015, before it was verified for the period from January 2016 to March 2017. Skill assessment of the model performance included visual comparisons and statistical quantifications of the difference between measured real-time data and model results. Both have shown that the LAMFE model performs well in simulating hydrodynamics, salinity transport, and thermal dynamics in the estuary. The good agreement of model results with field data suggests that the estimation of unquantified or missing SGDs in the spring-fed estuary is reasonable.