This is the appearance of the Parameters tab of the System Coefficients dialog:
Following is a description of the parameters associated with Parameters. Refer to the main System Coefficients page for information on other categories of coefficients. To save the changes made when closing this dialog, click OK. To ignore changes, click Cancel.
There are ten categories of coefficients which are chosen in the box at the top. The Names category has the following coefficients:
Abbreviation is an abbreviation for the parameter used in several places in the graphical user interface.
Fortran Code is a code recognized by the simulator to indicate a particular parameter.
Units is the units used for input and output in the graphical user interface.
The Output Control category has the following coefficients:
Master indicates whether or not any output for the parameter is to be saved.
Catchments indicates whether output for the parameter is saved for catchments.
Rivers indicates whether output for the parameter is saved for rivers.
Reservoirs indicates whether output for the parameter is saved for lakes/reservoirs.
Loading indicates whether loading output for the parameter is saved.
The Physical Data category has the following coefficients:
Charge is the sign of the ionic charge (-1, 0, or 1)
Equivalent Wt. is the mass conversion between equivalents used in the simulator and the units under the Names category used by the graphical user interface (>0, usually g/eq)
Dry Deposition is the mode by which the constituent is deposited on the ground surface and on vegetation. Aerosols are deposited at the gaseous deposition rate, and particles are deposited at the particulate deposition rate.
Advected indicates of the parameter is transported with water. Periphyton and fish are examples of parameters which are not advected.
The Hydroxide and Sulfate Solubility categories are used for the formation of solid precipitates or complex ions and have the following coefficients:
Solubility Product is the molar solubility product for the applicable precipitate or complex ion (>0, units vary and are empirical). Leave blank to indicate no solubility limit or complex ion formation.
Cation Valence is the valence of the listed ion in the precipitate or complex ion (>0 if there is a solubility product).
Anion Valence is the valence of hydroxide or sulfate in the precipitate or complex ion.
The Multipliers category has the following coefficients:
Point Sources is a management multiplier applied to all point sources (1 by default)
Nonpoint Sources is a management multiplier applied to all nonpoint sources (1 by default)
Atmos. Deposition is a management mulitplier applied to all wet and dry atmospheric deposition (1 by default)
The Composition category describes the components of parameters which are not directly calculated, but rather are the sum of other parameters. Enter what is multiplied by each parameter in equivalents to get the composite parameter in equivalents.
The Reactions category has the following coefficients for each reaction:
Reactant is the primary reactant for the reaction
Anoxic indicates whether the reaction is anoxic (occurring only below the anoxic limit)
UV Light indicates whether the reaction is catalyzed by ultraviolet light. UV light is absorbed in the top of the water column, within the Depth of Radiation Fraction.
Theta is the Arrhenius temperature adjustment coefficient (1.0 – 1.1, unitless)
Linked Reaction is another reaction upon which the given reaction is dependent. The rate of the given reaction is proportional to the amount of reactant consumed by the linked reaction.
The Reaction Products category contains the equivalents of each parameter produced in each reaction. The main reactant is not included but each reaction applies to one equivalent of main reactant. A negative value indicates that a parameter is consumed in the reaction.
The Gaseous Deposition Velocity category has monthly deposition velocities for those parameters whose Dry Deposition mode under the Physical Data category is Gaseous. (0-3 cm/s)