File name
RiverSystem.Plugins.PerfectGWLag.dll
Description
This plugin allows you to model groundwater and its interactions in a sub-catchment.
After installation, next steps involve creating a sub-catchments scenario with the Geographic Wizard for catchments, and configuring various parameters to model groundwater. Just as with any catchments scenario, use the wizard to first create a standard set of sub-catchments to suit your study area and modelling requirements in Define the network (Step 3).
Next define the functional units using a shape file (refer to Specify functional units (Step 5) for details) and assign areas to them using a raster (Specify functional unit areas (Step 6)). Figure 1- shows an example of this. The next section provides details on configuring rainfall runoff, constituent generation and filter models in Source.
Figure 1. Geographic Wizard- Assigning Functional Unit Areas
Defining and assigning models
You can then assign models to rainfall runoff, constituent generation, and any filtering you wish to the subcatchments using the wizard or the options in the Edit menu (refer to Rainfall runoff models and Constituents for details):
Constituent generation – You can add “Salt” as a constituent and assign the “Simple GW salt model”;
Rainfall runoff – assign “PERFECT GWLag” as a model. To assign inputs, choose PERFECT GWLag model input assignment from the Available Methods drop down menu (Figure 167) and load the weather database you wish to use. Check the following:
- the station number from each FU (left hand column) match the station numbers on the right hand side (drop down lists, right hand columns). If they do not, the entry on the right hand side will be the closest text based match, not the closest geographic match. You can adjust the matches by selecting an alternate station from the drop down list of stations available in the loaded weather database;
- Note that the minimum and maximum dates will be displayed by default. To save memory you can either import the desired time period or import the entire range but run the model for a selected period. The latter is a more flexible option.
Filter – Assign any filter model you wish from the drop down menu;
Links – you can add a model to selected links and if flow routing or a storage model is required. Note that there is no link model specific to the Groundwater tools in Source; and
Nodes – select FlowScaledLossModel from the Node models drop down list and click Add Model.
Figure 2. Geographic Wizard - Assigning Inputs to Rainfall Runoff Models
Parameterising models
This section describes how to parameterise each of the assigned models. It requires the parameterisation of both components – PERFECT and GWLag.
Rainfall runoff
Choose PERFECT-GWLag model parameterisation from the Available Methods drop down list. The PERFECT and GWLag parameters are specified under separate tabs
To parameterise PERFECT:
Select the Landuse tab under Perfect Parameters and click Load. Import the land use database in the same way
Once the database is loaded, check and adjust the crop and soil parameter associations. You may also choose to set the initial conditions such as “Proportion of Field Capacity” or “Crop Residue” Select the Soil tab under Perfect Parameters and click Load. Repeat the process for land use by loading a soils database for specifying soil association groups.
Figure 3. Parameterise Rainfall runoff model – PERFECT
GWLag
To parameterise the GW Lag components, click on the Lag GW parameters tab (shown in Figure 4):
• Set all the global parameters; these can either be changed individually or all at once. To set individually click on the appropriate cell and type a new value. To make changes to all values in a column (e.g. one parameter) change one cell to the desired value. Next right-click in a cell either above or below (in the same column) and select Apply to all sub-catchments from the contextual menu;
• Specify the groundwater parameters by importing them from a GFS shape file. Click Load in the Ground Flow System parameters group box and load a GFS shape file;
• Next, match the fields for aquifer thickness, hydraulic conductivity and storativity from the loaded GFS shape file by selecting the appropriate field name from each of the three drop-down lists; and
• Click Apply.