The Water Column Viewing Option is the primary 2D viewer for all of the water column related parameters as shown in Figure 1. The water column may be viewed by layer or by depth. For the former, the first options to set are the Layer Settings. There are three layering options for processing the water column data. They are Depth Avg for depth averaged results, Bot Layer for viewing the bottom active water column layer (this varies in the GVC model, standard sigma model this is layer 1) and a specified layer.

When viewing sediments or toxics the Total Seds/Total Tox and Sed Class/Tox Class are used to decide how to treat the display results, i.e. as totals or by class.

The data displayed in the 2D plot can be edited using the editing tools available if the current time is set to the initial conditions.

The options listed in the Options frame will only be enabled if the correct computational flags are set. The Density option is only available if salinity and/or temperature are being simulated. If only salinity is simulated the temperature is taken as a constant 20°C.

For most Viewing Opt's the Statistics tool on the toolbar is available to compute a range of statistics on the current view. For the Water Column option the Statistics tool provides additional capability. The Statistics tool can compute a time series of the mass weighted averages for any parameter for all or any subset of the model.

Figure 1  ViewPlan: Viewing Option for Water by Layer.

Water Quality

If water quality is being simulated the Wtr Quality option button is enabled as is the parameter dropdown list. In addition to the 22 EFDC water quality parameters, EFDC_Explorer has 26 derived parameters that can also be displayed. Table 1 provides a complete list of the EFDC and EFDC_Explorer derived parameters.

The kinetic subroutines in EFDC allow the parameters to be turned on and off, depending on the level of detail in a model. However, when a parameter is not turned on it still has a value (i.e. the initial condition) and may be used in the kinetic equations of parameters that are being simulated. Therefore, EFDC_Explorer always allows the display of all EFDC parameters. However, to make it clear as to which parameters were simulated and which were not, a "(NS)" is placed at the end of the parameter abbreviation shown in the dropdown list for those parameters not simulated.

For the EFDC_Explorer derived parameters a "(DP)" is placed on the end of the abbreviation to clearly indicate that the parameter was derived.

Irradiance

The ability to determine the % Bottom Irradiance can useful when the user is interested in cases where the amount of light penetration must be determined, such as where there are macrophytes or aquatic vegetation. Note that this tool only determines the potential for irradiance, and does not allow for day or night or factor in cloud cover etc.

Select Other option, from the parameter dropdown list, select % Irrad Water or % Irrad bottom, the result can be displayed as in Figure 2 and Figure 3.

Pressing Alt+B accesses the Bottom Irradiance Tool. The user is first prompted for analysis of a polygon, which must then be loaded, or the whole model.

The subsequent option form is shown in Figure 4. The user should enter the Maximum Bottom Depth in meters. Cells deeper than this depth are displayed as white. As depths will vary due to tides it is usually most useful to calculate an average for the Depth Criteria Approach. The user should finally enter the Irradiance Target as a percentage. EFDC_Explorer will then calculate all the cells that fit the criteria and calculate statistics for those cells.

Figure 4  ViewPlan: Water Column, % Irradiance Tool.

Table 1  Water quality parameter list available for display.

Habitat Analysis

The user may undertake a habitat analysis of the water column when the Water by Layer drop down is selected as shown in Figure 5. This tool is access by Alt+H. The user may analyze any of the parameters displayed in the Options in frame in the right hand column. The user should set critical levels (in this case temperature, ^oC), critical depths and critical duration (in hours) and press Display. EFDC will then calculate the number of cells for which these criteria apply, displaying the area and volume in the yellow Habitat Criteria box, as well displaying the critical cells. A second critical duration may also be displayed concurrently.

The user may undertake several kinds of habitat analysis from ViewPlan by selecting Alt+H.  This will open the EEMS Habitat Tools option form as shown in Figure 6.  Select 1, 2, or 3, for the Thermal and Depth Criteria Limits, Critical Limits, or HSC options respectively.  The latter two options are only available if they have been correctly configured as described in Habitat Analysis.

Figure 5  ViewPlan: Habitat tools.

The most basic option is option 1, Thermal and Depth Criteria Limits. This analysis tool was initially implemented to support studies on Manatee (a.k.a. Sea Cow; Trichechus manatus) populations in the Chassahowitzka Estuary.  This kind of analysis of the water column is available when the Water by Layer drop down is selected as shown in Figure 6.  The user may analyze any of the parameters displayed in the Viewing Options frame.  In the Critical Habitat Analysis form the user should set critical levels (in this case temperature, ^oC), critical depths and critical duration (in hours) and press Display.  EE will then calculate the number of cells for which these criteria apply, displaying the area and volume in the yellow Habitat Criteria box, as well displaying the critical cells. A second critical duration may also be displayed concurrently.

Figure 6  ViewPlan: Water by Layer, Habitat Analysis tool.

Selecting option 2 or 3 will cause EE to prompt the user for the habitat limits or criteria file. EE will then display areas satisfied by the criteria, as shown in Figure 7. This option is available for all the parameters that may be set in the habitat critical limits, or suitability criteria.  If a cell is dry it is shown as grey. For the critical limits the default color ramp is white (0) to green (1).  For habitat suitability criteria the same principle applies, however shades of green from 0 to 1 are displayed.

Figure 7  ViewPlan: Habitat criteria limits.