Particle Tracking and Delineation
This tool allows visualizing particle locations and particle pathlines for any time-step in a transient model. (In the Post Analysis tool, only the last time-step will show the particle locations and/or particle pathlines. Previous time-steps will only show flow and plume modeling results.)The tool also allows delineation of downstream or upstream impact areas (i.e., particle pathline envelopes) for different travel times, which can be exported as GIS shapefiles.
A. Particle File
B. Select time-step for analysis
C. Do Delineation
D. Create additional shapefile feature(s)
E. Editing an existing feature
A. Particle File
Begin by selected "Curret Model" (last executed groundwater model) or by importing a IGW-NET particle file.IGW-NET particle files are generated after the following is completed:
1) Before simulation, 'Save PTK results' box is checked under Particle Tracking Options (Conceptual Model Tools > DomainAttr > Simulation Settings tab).
2) Perform simulation (groundwater flow and particle tracking)
3) Save latest particle tracking results (Other Tools > SaveModel > Latest Particle Results)
Clicking 'Apply' will load the particle display options (see next).
B. Select time-step for analysis
Use the Time Step drop-down menu to select the time-step for analysis (days from start of simulation).Select Load to show particles and pathline at the chosen time-step. Note that this is not necessary to do delineation (i.e., you can skip this Loading step).
Other options are available for particle display (e.g., Hide/Show results, add particle pathelines, particle symbol size).
C. Do Delineation
Start a new delineation
Click the chevron button (>> >>) next to Delineation to expand the options. Check the box next to 'Save to Shape file' and select New. Note that this will overwrite any previously created shapefile feature(s) saved to the user folder on server. You can download the existing shapefile first, if you need it.Edit Field attributes
Click Field Edit to expand options for adding or editing shapefile field attributes. By default, the following fields are created and autopopulated:- Site Name
- Travel time (years since start of particle tracking)
- Type (e.g., contamination impact area for source water area
- Created by (MAGNET4WATER username by default)
- Date
- Comment
Make sure to click 'Save Field' to finish editing existing fields or after adding a new field (Add button).
Select delineation method
Concave Hull is an ideal method of particle pathlines bend or have significant curvature. Note that you may need to use a small alpha value, e.g., 0.05 or 0.01 to get meaningful delineations.Convex hull is a more robust method but may overestimate impact areas/source area if paricle pathlines bend or have significant curvature.
Manual delineation is done by drawing on the map and clicking SaveShape to finalize the impact area/source area (Conceptual Model Tools > ShapeShape).
Perform delineation
Click the 'Do Delineation' button to start the process.D. Create additional shapefile feature(s)
1. Change Time Step for analysis2. Select Append to under 'Save to shape file'. *This adds the new features to the existing PTK shapefile (Rather than creatiuing a new shapefile - the latest).
3. Edit field attributes, e.g., change Travel Time and Comment box to reflect new time-of-travel being analyzed.
4. Select Delineation Method