< Previous50 Figure 4-19: Sub-menu for editing transient prescribed head data. Prescribed Source Concentration. A zone can be assigned a solute source concentration for all model cells over which it extends for the purposes of transport modeling. To do this, check the radio box next to ‘Source Concentration’. To apply an instantaneous (delta-function) source concentration, select the radio button next to ‘Instantaneous:’ and enter a value (units: ppm) in the text box provided. To apply a continuous concentration (i.e. constant in time), select the radio button next to ‘Continuous:’ enter a value (units: ppm) in the text box provided To assign time-varying source concentration, check the radio box next to the ‘Transient’ button, and then LM click the ‘Transient button Check the radio box next to the ‘Transient’ button to open the Transient Data for Lake Concentration sub-menu (see Figure 4-20). Indicate the starting data and time with the text boxes next to ‘State Date’ (year, month, day, hour). Then, provide the following inputs for each timestep: TimeN – or the number of days since the starting date and time; and ValueN – the concentration value corresponding to TimeN. The concentratoin values may be entered in any units; however, if ppm are not used, make sure to enter the appropriate multiplier in the text box next to ‘Multiplier to ppm’. After all desired changes have been made, LM click the ‘OK’ button. Or click ‘Cancel’ to discard all changes and close the sub-menu. 51 Figure 4-20: Sub-menu for editing transient source concentration data. 4.2.7 Editing Attributes of Existing Zones When the simulation is complete/paused, any pre-exiting zone feature can be edited by clicking the ‘AttrZones’ button from left-side of the MAGENT Modeling Environment. All pre-existing zones are then filled red within the model domain (see Figure 4-21). Click once within the zone to be edited, and select ‘OK’ from the prompt to confirm editing. This opens the Zones Attributes menu for updating parameters/options of the polyline feature. Click ‘Save and Exit’ to apply the changes to the zone feature, and continue editing other zone features, if desired. Once all changes have been made, click on the ‘AcceptEdits’ button on the left-side of the MAGNET Modeling Environment. This applies all updates and turns the zone back to green (unfilled) objects in the MDWA. 52 4.3 Well Features & Attributes Wells can be added to the model domain to: • add pumping stress or a source of water (e.g., injection well) at a point location • add a point-source of a pollutant/solute in groundwater • place particles at a point location or in a circle around a point location (see Section 5.6) • monitor simulation results (both head and concentrations) and compare with observations (see Section 6.1). To add a well feature to the model domain, LM click on the ‘Well’ button along the left-side of the MAGNET Modeling Environment (see Section 2.5). The cursor will become a cross-hair, allowing for placement of a well with a single-click of the LM button. This will open the Well Input Options menu (see Figure 4-22). The coordinates (latitude and longitude) of the well feature are displayed in degree-decimal form in the text boxes next to ‘Lat:’ and ’Lon:’.9 9 The location of any well can be updated by entering new values in these text-boxes, then hitting ‘OK’. Figure 4-21: attributes of pre-existing zone features. 53 Figure 4-22: Well Input Options menu. 4.3.1 Well Features as Pumping/Injection Wells By default, the pumping rate is equal to zero. To make the well a sink (pumping stress), enter a negative value in the text box next to ‘Pumping Rate:’, or enter a positive value to conceptualize it as an injection well. The value that is entered is used for steady-state pumping (i.e., the rate does not change with time). The default location of the well screen will be centered at a distance from the surface that is two-thirds the depth of the aquifer at that location. The user may specify the screen top elevation and bottom elevation by entering non-zero values (units: meters) in the text boxes next to ‘Screen Top:’ and ‘Screen Bot:’, respectively. To implement a time-varying pumping/injection rate, check the radio box next to ‘Transient’, then LM click on the ‘Transient’ button. This opens the Transient Data for Pumping/Injection Rate sub-menu (see Figure 4-23). Indicate the starting data and time with the text boxes next to ‘State Date’ (year, month, day, hour). Then, provide the following inputs for each timestep: TimeN – or the number of days since the starting date and time; and ValueN – the pumping rate value corresponding to TimeN. The pumping rates may be entered in any units; however, if m3/day are not used, make sure to enter the appropriate multiplier in the text box next to ‘Multiplier to m3/day:’. After all desired changes have been made, LM click the ‘OK’ button. Or click ‘Cancel’ to discard all changes and close the sub-menu. 54 Figure 4-23: Sub-menu for editing transient pumping/injection rate data. 4.3.2 Well Features as a Point Source To use a well feature a point source (e.g., an injection well) of pollutants/solutes, enter a non-zero number in the textbook next to ‘Conc:’ (units: ppm)10. The value that is entered is used as source concentration for all time steps (i.e., the well functions as a continuous source). See Sections 5.2 and 6.1 for details on visualizing solute/contaminant transport results. To implement a time-varying source concentration, check the radio box next to the ‘Transient’ button, then LM click on the ‘Transient’ button. This opens the Transient Data for Injecting Source Conc Rate sub-menu (see Figure 4-24). Indicate the starting data and time with the text boxes next to ‘State Date’ (year, month, day, hour). Then, provide the following inputs for each timestep: TimeN – or the number of days since the starting date and time; and ValueN – the concentration value corresponding to TimeN. The concentrations may be entered in any units; however, if ppm are not used, make sure to enter the appropriate multiplier in the text box next to ‘Multiplier to ppm’. After all desired changes have been made, LM click the ‘OK’ button. Or click ‘Cancel’ to discard all changes and close the sub-menu. 10 A positive pumping rate must be entered in the text box next to ‘Pumping Rate’ for the well to function as a point source. The resulting mass flux of the pollutant/solute from the point source is: (pumping rate)*(concentration). 55 Figure 4-24: Sub-menu for editing transient injection source concentration data. Placing Particle at a Well Location. Adding particles around wells and then performing backward particle tracking is a very useful way to delineate well capture zones. To add particles around a well, check the radio box next to ‘Add Particle’. The number of particles placed around a well can be controlled accessing the Default Parameters and Options menu by clicking on the ‘DefaultInput’ button along the left-side of the Magnet Modeling Environment (see Section 2.7). In the Particle Tracking option box, adjust the number pf particles around a well by entering a value in the text box next to ‘Particle # Around a Well:’ (see Figure 4-25). The particles will be placed a radial distance from the well location determined by the value (units: meters) entered in the text box next to ‘Particle Well Radius:’. See Section 5.6 for complete details on the particle tracking capabilities and options available in MAGNET. Figure 4-25: Particle tracking options available in the Default Parameters and Options menu. Default values/settings are shown. 56 4.3.3 Well Features as Monitoring Wells The Well Input Options can also to create a monitoring well at the location of the placed well feature. To do so, check the radio box next to ‘Monitoring Well’. When the model is simulated/run forward, a time-series plot for head and/or concentration will be available in the Monitoring Wells Plot chart when analyzing model results with the ‘ViewResult’ button (see Section 6.1). Including Observational Data. To include transient head and/or solute concentration observations in the monitoring well plots, check the radio boxes next to ‘Observation H’ and ‘Observation C’ button. To input transient head data, LM click on the ‘Observation H’ button. This opens the Transient Data for Head Observation sub-menu (see Figure 4-26). Indicate the starting data and time with the text boxes next to ‘State Date’ (year, month, day, hour). Then, provide the following inputs for each timestep: TimeN – or the number of days since the starting date and time; and ValueN – the head value corresponding to TimeN. The head values may be entered in any units; however, if meters are not used, make sure to enter the appropriate multiplier in the text box next to ‘Multiplier to meter’. After all desired changes have been made, LM click the ‘OK’ button. Or click ‘Cancel’ to discard all changes and close the sub-menu. To input concentration data, LM click on the ‘Observation H’ button. This opens the Transient Data for Head Observation sub-menu (see Figure 4-27). Indicate the starting data and time with the text boxes next to ‘State Date’ (year, month, day, hour). Then, provide the following inputs for each timestep: TimeN – or the number of days since the starting date and time; and ValueN – the concentration value corresponding to TimeN. The concentrations may be entered in any units; however, if ppm are not used, make sure to enter the appropriate multiplier in the text box next to ‘Multiplier to ppm’. After all desired changes have been made, LM click the ‘OK’ button. Or click ‘Cancel’ to discard all changes and close the sub-menu. 57 Figure 4-26: Sub-menu for editing transient head observations. Figure 4-27: Sub-menu for editing transient concentration observations. 4.3.4 Editing Existing Well Features 58 After well inputs have been finalized, the well feature will appear as a yellow circle in the model domain (see Figure 4-28). To edit or delete any existing well feature, hover the cursor over it and LM click. This brings up the Well Input Options for that feature. Edit as desired, then LM click ‘OK’. Or delete the well feature by LM clicking on the ‘Delete’ button. Figure 4-28: Example of a well feature placed in a model. 59 Chapter 5 SIMULATION AND VISUALIZATION As described in Chapter 1, MAGNET is designed so that any model can be simulated with results provided in “real-time” (i.e., nearly instantaneously if a modest number of grid cells and conceptual features are used). The results can be used to guide model editing or to build new, nested models for more detailed local analysis (see subsection 3.6.1). This chapter explains how to simulate and run a model and view the model results. 5.1 Submitting a Model for Simulation Once the model domain has been created, a user may submit the model (or “job”) for simulation by clicking on the red ‘SIMULATE’ button on the left-side of the MDWA (see section 2.4). The first time a job is submitted, the user must provide their account credentials, i.e., username and password (see Section 1.3). All subsequent job submissions during the web session will not require entering user credentials. Note that users need not change any default inputs/options or add any conceptual features in order to run a model. This “one-click” steady-state modeling approach allows users to quickly see the large-scale, prevailing flow patterns that are largely controlled by the topographic framework (see Curtis et al., in preparation), which is by default set as the top aquifer elevation surface (see subsection 3.3.1). Once the model has been submitted for simulation, MAGNET will automatically search for the appropriate geographic projection (‘PRJ’) to use based on the region used for modeling. A prompt will appear asking the user to accept the projection (LM click the ‘OK’ button) or use the default projection (click the ‘Cancel’ button). See the following sub-section for details on defining the default projection. 5.1.1 Defining the Default Projection System To define a default projection system to use for modeling, navigate to the Default Parameters and Options menu by LM clicking on the ‘DefaultInput’ button along the left-side of the MAGNET Modeling Environment (see Section 2.7). LM click the ‘Browse’ button next to ‘Load PRJ’ in the Projection option box (see Figure 5-1). This will open a window to browse to a file for uploading. After the projection system file is loaded, the system details will be shown in the large text window below the name of the current default projection system11. 11 By default, the NAD_1983_NSRS2007_Michigan_GeoRef_Meters (State of Michigan) projection system is used in MAGNET. Next >