WMS:GSSHA Contaminants: Difference between revisions

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To model contaminants in GSSHA the contaminant transport option in the ''Job Control'' dialog must be turned on.  
 
Modeling contaminants in GSSHA requires turning on the ''Contaminant transport'' option in the [[WMS:GSSHA Job Control|''Job Control'' dialog]].  


Contaminants are set up in three steps:
Contaminants are set up in three steps:
#Set up the contaminant types.
#Set up the contaminant types.
#Create the index maps for the contaminants.
#Create the index maps for the contaminants.
#Set up the contaminant parameters in the mapping table.
#Set up the contaminant parameters in the mapping table.


===Set up the contaminant types===
==Contaminant Types==
 
[[Image:GSSHA_Contaminants.jpg|thumb|right|425 px]]
Contaminants are defined in the ''GSSHA Contaminants'' dialog, which is accessed either in the ''GSSHA'' menu or from the ''Job Control'' dialog. Click on '''Add''' to add new contaminants. Five parameters must be defined for each contaminant:
Contaminants are defined in the ''GSSHA Contaminants'' dialog, which is accessed by turning on ''Contaminant transport'' in the ''Job Control'' dialog, then clicking '''Edit parameter...''' to the right of the option. The following options are available:
#A description of the contaminant.
*'''Add''' – Creates a new contaminant entry in the spreadsheet section of the dialog.
#An index map showing the spatial distribution of the contaminant.
*'''Delete''' – Immediately deletes the selected contaminant entry in the spreadsheet section of the dialog.
#The GSSHA output base filename for that contaminant.
#Concentration of the contaminant in rainfall.
#Soil water partition coefficient.
 
Note that the index map for each contaminant may be specified in the ''GSSHA Contaminants'' dialog or the ''GSSHA Index Map Table Editor'' dialog.
 
[[Image:GSSHA_Contaminants.jpg|thumb|none|left|425 px]]
 
===Create the index maps for the contaminants===
 
The next step is to create [[WMS:GSSHA Maps|index maps]] for the contaminants. These index maps are created in the same manner as other index maps and will usually be a cross between a soil type and a contaminant distribution coverage. However, there is no contaminant distribution coverage type in WMS. Simply create either a land use or soil type coverage and create polygons representing the different contaminant plumes. Different polygons for different initial concentrations of the contaminants will be useful later on as the specified contaminant concentration level for each index map ID (polygon) is a uniformly distributed concentration over the polygon. Also, in the coverage representing contaminants the entire grid must be covered by a polygon. Outside the contaminant plumes, the concentration will be zero.  
 
When creating the index map from the coverages, a cross between a soil type and the contaminant distribution coverage will prove to meet the needs of the contaminant transport routines. The parameters that must be specified for each index map ID are a dispersion rate of the contaminant in standing water, a decay rate for the contaminant (first order kinetics), a cell uptake rate, and an initial mass loading. The contaminant distribution coverage should be used to define the initial mass loading and the soil type coverage should be used to define the cell uptake rate. The dispersion and decay rates will typically be uniform throughout the grid.
 
===Set up the contaminant parameters in the mapping table===
 
Finally, go to the GSSHA Index Map Table Editor. Choose one of the contaminants that have been set up and associate the correct index map with it. Follow the usual steps for setting up an index map and initialize each of the parameters for each ID.
 
''Contaminant Parameters''
 
*Dispersion rate (''m<sup>2</sup> s<sup>-1</sup>'')
 
*Decay rate (''s<sup>-1</sup>'')


*Cell uptake coefficient  
In the spreadsheet section are the following columns:
*''Description'' &ndash; Contains an alphanumerical description of the contaminant. This should be unique in order to avoid confusion when reviewing output reports and charts.
*''Index Map'' &ndash; Drop-down menu of all of the index maps in the project. Select the one to be used with the contaminant. This can also be specified in the [[WMS:GSSHA Mapping Tables|''GSSHA Map Table Editor'' dialog]].
*''Precipitation Concentration'' &ndash; A ratio of contaminant to transport medium (rainfall). The default unit is mg/l.
*''Partition'' &ndash; The soil water partition coefficient. A higher number indicates a higher likelihood of the contaminant adsorbing onto soil particles.
*''Base Output Filename'' &ndash; Displays the path and file name for the output file for that contaminant.


*Initial mass loading (kg)
==Contaminant Index Maps==


*Groundwater concentration (mg/l)
Contaminant [[WMS:GSSHA Maps|index maps]] are created in the same manner as other index maps and will usually be a cross between a soil type and a contaminant distribution coverage. However, there is no contaminant distribution coverage type in WMS. Simply create either a land use or soil type coverage and create polygons representing the different contaminant plumes. Different polygons for different initial concentrations of the contaminants are useful because the specified contaminant concentration level for each index map ID (polygon) is a uniformly distributed concentration over the polygon. Note that in the coverage representing contaminants, the entire grid must be covered by a polygon. Outside the contaminant plumes, the concentration will be zero.


*Initial concentration (mg/l)
The parameters that must be specified for each index map ID are:
*A dispersion rate of the contaminant in standing water,
*A decay rate for the contaminant (first order kinetics),
*A cell uptake rate, and
*An initial mass loading.


*Soil water distribution coefficient
The contaminant distribution coverage should be used to define the initial mass loading and the soil type coverage should be used to define the cell uptake rate. The dispersion and decay rates will typically be uniform throughout the grid.


*Max concentration/solubility (mg/l)
==Contaminant Parameters Mapping Tables==


The contaminant parameters are set by selecting ''GSSHA'' | '''Map Tables...''' to bring up the [[WMS:GSSHA Mapping Tables|''GSSHA Map Table Editor'' dialog]], then select the [[WMS:GSSHA Mapping Tables#Contaminants|''Contaminants'' tab]].





Revision as of 17:07, 15 April 2019


Modeling contaminants in GSSHA requires turning on the Contaminant transport option in the Job Control dialog.

Contaminants are set up in three steps:

  1. Set up the contaminant types.
  2. Create the index maps for the contaminants.
  3. Set up the contaminant parameters in the mapping table.

Contaminant Types

GSSHA Contaminants.jpg

Contaminants are defined in the GSSHA Contaminants dialog, which is accessed by turning on Contaminant transport in the Job Control dialog, then clicking Edit parameter... to the right of the option. The following options are available:

  • Add – Creates a new contaminant entry in the spreadsheet section of the dialog.
  • Delete – Immediately deletes the selected contaminant entry in the spreadsheet section of the dialog.

In the spreadsheet section are the following columns:

  • Description – Contains an alphanumerical description of the contaminant. This should be unique in order to avoid confusion when reviewing output reports and charts.
  • Index Map – Drop-down menu of all of the index maps in the project. Select the one to be used with the contaminant. This can also be specified in the GSSHA Map Table Editor dialog.
  • Precipitation Concentration – A ratio of contaminant to transport medium (rainfall). The default unit is mg/l.
  • Partition – The soil water partition coefficient. A higher number indicates a higher likelihood of the contaminant adsorbing onto soil particles.
  • Base Output Filename – Displays the path and file name for the output file for that contaminant.

Contaminant Index Maps

Contaminant index maps are created in the same manner as other index maps and will usually be a cross between a soil type and a contaminant distribution coverage. However, there is no contaminant distribution coverage type in WMS. Simply create either a land use or soil type coverage and create polygons representing the different contaminant plumes. Different polygons for different initial concentrations of the contaminants are useful because the specified contaminant concentration level for each index map ID (polygon) is a uniformly distributed concentration over the polygon. Note that in the coverage representing contaminants, the entire grid must be covered by a polygon. Outside the contaminant plumes, the concentration will be zero.

The parameters that must be specified for each index map ID are:

  • A dispersion rate of the contaminant in standing water,
  • A decay rate for the contaminant (first order kinetics),
  • A cell uptake rate, and
  • An initial mass loading.

The contaminant distribution coverage should be used to define the initial mass loading and the soil type coverage should be used to define the cell uptake rate. The dispersion and decay rates will typically be uniform throughout the grid.

Contaminant Parameters Mapping Tables

The contaminant parameters are set by selecting GSSHA | Map Tables... to bring up the GSSHA Map Table Editor dialog, then select the Contaminants tab.