Table 2.1 NOAA Tide Data Tide Data Mean Higher High Water (MHHW) Mean High Water (MHW) Mean Tide Level (MTL) Mean Low Water (MLW) Mean Lower Low Water (MLLW) Tide Range (ft) (MHW – MLW) 2.4
Jupiter Inlet Jetty (ft-NAVD) 0.25 0.08 -1.11 -2.31 -2.50 2.39
Model Parameters and Boundary Conditions
A Manning’s roughness coefficient (Manning’s n) value of 0.030 provided the bed friction boundary condition within the model. The Florida Department of Transportation recommends n = 0.022 – 0.028 for earth channels (FDOT, 2004); the USACE recommends n = 0.02 – 0.025 for sand channels (Donnell et al., 2005); Chow (1959) recommends n = 0.035 for rivers. A turbulent exchange coefficient value of 50 lb-sec/ft2 controlled the turbulence closure for the hydrodynamic model. This value falls well within the 20 – 100 lb-sec/ft2 range the model developers recommend for flow in tidal estuaries (Donnell et al., 2005). Grid Peclet number control automatically assigned the model diffusion coefficient for the transport model. The actual diffusion coefficient averaged 3 ft2/s (0.3 m2/s) or less for all model simulations. The model calibration applied time-varying free surface water level boundary conditions from September 16 – 20, 2008 at Hobe Sound, seaward of Jupiter Inlet, and Lake Worth Creek. NOAA tide predictions provided water level boundary conditions for the model. 2.5
Model Calibration Results
A model’s calibration demonstrates its capability to reproduce observed hydrodynamic conditions. Figures 2.7 and 2.8 compare the modeled water levels with the measured water levels at the Marina Tide Station and NOAA predicted water levels at the Jupiter Inlet Jetty Station. The correlation coefficient provides a statistical measure of the correspondence of two data sets. Two coincident data sets have a correlation coefficient of 1.0 (i.e., the data sets match), while correlation coefficients approaching zero indicate less correspondence between the data sets. The figures indicate the correlation coefficient (r2) for each time series. The modeled and measured water level data show good agreement for both stations with correlation coefficients of 0.97 or more.
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