Algae and Macrophyte Options

EEMS allows users to simulate an unlimited number of algal and macrophyte groups, with each group assigned different parameters such as half-saturation constants and uptake rates for nutrients according to the aquatic ecosystem model. In the Macrophyte and Algae Options frame, users should input the number of algal groups to be simulated as Figure 1. Click the Modify button to being editing parameters for each group. The macrophyte parameters are classified flowing its kinetics processes in each sub-tab. 

Figure 1.  Macrophyte and Algae Options.

1. General 

In the General tab (Figure 2), input the name for the algal group and other parameters.

With the new macrophytes options in EFDC+, biota can be mobile or fixed. If the Is Mobile box is unchecked. The Fixed Biota subtab can be enabled. 

Figure 2. Macrophyte and Algae Options: General.

2. Growth

The process of algae growth is described in the Growth sub-tab ( as shown in Figure 3) with growth parameters and optimal temperature options. 

Figure 3. Macrophyte and Algae Options: Growth.

3. Basal Metabolism

Figure 4 shows the Basal Metabolism sub-tab includes General Options, Basal Metabolism Nutrient Fractions, Algae DOC Excretion, and Optimal Temperature Options. 

Figure 4. Macrophyte and Algae Options: Basal Metabolism.

4. Predation

Figure 5 shows the Predation sub-tab. If the box of Winter Bloom in General Options is checked, the Optimal Temperature Options will enable. 

Figure 5. Macrophyte and Algae Options: Predation.

5. Diagenesis

When using Full Diagenesis Model option in Sediment Fluxes, the tab of Diagenesis is available as in Figure 6.

Figure 6. Macrophyte and Algae Options: Diagenesis.

6. Fixed Biota

The fixed biota parameter is presented in the Fixed Biota sub-tab ( as shown in Figure 7)

Note that: the Maximum Length/Height is only considered when the Threshold to Allow Growth between Layers is set to zero. When there is no threshold, the macrophyte can grow between layers and reach any height. Therefore, a maximum height is needed in this case to control the macrophyte height. 

Figure 7. Macrophyte and Algae Options: Fixed Biota