Using EFDC Explorer to compare bathymetry between different models

Often times we will end up having two different bathymetry data sources and we would like to know how different those data sources are. Eventually, we will use those data to create bathymetry in EFDC model.

EFDC model allows an easy comparison between bathymetry at two different models.

For example, we will use an EFDC model of Ohio River which can be downloaded from EFDC Explorer website Continue reading


Dynamic time step in EFDC model

In EFDC Model there is an option to choose the dynamic time step. The subroutine which controls the dynamic time step is CALSTEPD.f90. In this subroutine, there are four method check which determine the time step. They are as follows:

1) Method 1: Upwind difference in momentum equations.
2) Method 2: Positivity of advected material.
3) Method 3: Implicit bottom friction and rotational acceleration damping
4) Method 4: Limit rate of depth change. Continue reading

Calibration parameters and their range in EFDC model

EFDC is not a self calibrated model. There are several parameters that can be tuned in EFDC model to calibrate the parameters. Calibration is a process of comparing the modeled results with the observed data. If the modeled data and observed data match close then it is said that the model is calibrated. There are several parameters that are used to quantify the calibration process. They are average error, relative error, average absolute error, RMS error, Relative RMS error, Nash-Sutcliffe Efficiency Coefficient.