💧 IGW-NET · Quick Tutorial 14 of 31

Tutorial 14: Post-Analysis Tools

Use IGW-NET post-analysis tools: head contours, flow vectors, drawdown, water table, zone budgets, and custom cross-sections.

IGW-NET Tutorial 14 Prereq: MAGNET4WATER account 3 sections

This tutorial covers

  1. Setting Up the Transient Simulation
  2. Model Post-Processing & Analysis
  3. What's Next

1Setting Up the Transient Simulation

Step 1 — Draw the Model Domain

Click Utilities Draw Domain to zoom to Fort Custer, Michigan and delineate the regional model domain.

Step 2 — Assign Data Server Inputs

Click Settings to open the Domain Attributes menu. Assign Data Server data layers as domain inputs for aquifer top elevations, bottom elevations, hydraulic conductivity, and recharge. The Global Base Model provides spatially variable properties automatically.

Step 3 — Run Steady-State Baseline

Click Submit to submit for steady-state simulation. This head distribution becomes the initial condition for the transient model.

Step 4 — Enable Transient Mode

Click Settings to reopen the Domain Attributes menu. In the Simulation Settings tab, enable transient flow:

Check: 'Modeling Transient Flow'
Start date: 5/12/2000 (May 12, 2000)
Time step: 90 days (~quarterly)
Simulation length: 2520 days (7 years)
Initial condition: 'Parent' (uses steady-state solution)

Step 5 — Increase Recharge

In the Aquifer Attributes tab, enter 1.35 in the recharge multiplying factor. This increases recharge to 135% of the Data Server value — simulating a wetter-than-average period and allowing observation of rising water levels over 7 years.

Step 6 — Run the Full Transient Simulation

Click Submit to submit and let the transient model run to completion (all 28 time steps over 7 years).

Fort Custer model domain showing Data Server inputs (aquifer top, bottom, K, recharge) and steady-state flow field with head contours and velocity vectors
Figure 1: Model domain with Data Server inputs and steady-state flow field — this becomes the initial condition for the 7-year transient simulation.
Domain Attributes menu showing Simulation Settings tab with transient flow enabled, start date 5/12/2000, time step 90 days, simulation length 2520 days, and recharge multiplier 1.35
Figure 2: Transient settings — 7-year simulation with quarterly time steps and 35% recharge increase.

2Model Post-Processing & Analysis

Step 1 — Open the Post-Analysis Tool

Click Analysis Tools then Post Analysis Analysis menu 'Analysis Tools' → 'Analysis' → 'Post Analysis'. Select 'Current or Last Model' and click Apply. This loads the completed transient simulation results and opens the Post-Analysis toolbar with all available tools.

Step 2 — View Results at Any Time Step

Expand 'View Result at Time Stamp' and select a timestamp from the scroll menu. The head distribution updates instantly in the map display — you can step through all 28 quarterly snapshots, watching 7 years of aquifer evolution frame by frame.

Step 3 — Extract a Monitoring Well Hydrograph

Expand the 'Monitoring Well' option and click Extract Monitoring Well chart 'Extract' to open a monitoring well time-series chart. The head history for a well near the center of the model is extracted and plotted — showing how water levels evolved over the 7-year simulation.

Step 4 — Add Another Monitoring Well Interactively

With the Post-Analysis menu still open, click Draw Well Well tool the 'Draw Well' tool to place a new monitoring well near the discharge area (bottom-right of domain). This well didn't exist during the simulation — the Post-Analysis tool extracts its time series retroactively from the saved results.

Step 5 — Compare Multiple Monitoring Wells

Click Extract 'Extract' again under Monitoring Well. In the MW Time Series Chart, expand the chart window, select both wells under 'Model Dataset', and click Redraw. Both hydrographs appear on the same chart — revealing how different locations respond differently to the same recharge increase. Recharge areas may show larger rises; discharge areas may show buffered, delayed responses.

Step 6 — Launch Transient Calibration

Expand the 'Calibration' option in the Post-Analysis menu and click Transient Calibration Chart 'Transient Calibration Chart'.

Step 7 — Import Observed Static Water Levels

In the Calibration Chart menu, select 'IGWServer' under 'Observed Data Sources' to import Static Water Levels (SWLs) live-linked from the MAGNET4WATER Data Center. These are real observed water levels from USGS and state monitoring networks — no manual data entry, no file preparation.

Step 8 — View the 45-Degree Calibration Chart

After importing observed SWLs, the calibration chart shows simulated head vs. observed SWLs across the entire model domain and simulation period. Points near the 1:1 line indicate agreement. Spread in the data reflects both spatial variability (different wells at different elevations) and temporal variability (7 years of changing conditions).

Step 9 — View the Observation Trend Chart

Click 'Draw Calibration Trend' to launch the Observation Trend Chart — a time-series plot showing simulated head and observed SWL temporal trends together. This reveals whether the model captures the overall direction and magnitude of water level changes over the 7-year period.

Post-Analysis tool interface showing the loaded transient results with head distribution at a selected time step, the time stamp selector, and monitoring well extraction tools
Figure 4: Time step viewer and monitoring well extraction — select any time step to update the head display, then extract a hydrograph showing the full 7-year water level history at that location.
MW Time Series Chart showing hydrographs for two monitoring wells — one in the recharge area and one near the discharge area — both showing rising water levels but at different rates and magnitudes
Figure 5: Two monitoring well hydrographs compared — different locations respond differently to the same 35% recharge increase. The recharge-area well rises faster; the discharge-area well shows a more gradual, buffered response.
Transient calibration workflow showing the IGWServer data import interface for extracting observed Static Water Levels, with data source selection and filtering options
Figure 6: Importing observed SWLs from the MAGNET4WATER Data Server for transient calibration — live-linked data from USGS and state networks, filtered by the model domain and simulation period.
Calibration Chart showing 45-degree plot of simulated vs observed heads across the domain and simulation period, alongside the Observation Trend Chart showing simulated and observed temporal trends
Figure 7: Calibration results — the 45-degree chart (left) compares simulated and observed heads across space and time. The Observation Trend Chart (right) overlays simulated and observed temporal trends. The spread reflects both spatial variability across wells and temporal variability across 7 years.

Key Concepts

Retroactive monitoring wells: You don't need to plan every monitoring location before running. The Post-Analysis tool lets you place wells after the simulation — extracting time series from saved results at any xy location. This is invaluable for exploratory analysis: "What happened at this point?" Click, extract, answer.

Live-linked observed data: The connection to the MAGNET4WATER Data Server means calibration data is always current. As new SWL observations are added to USGS or state databases, they become available in IGW-NET without any user action. Run a model today, calibrate against data collected yesterday.

Spatial + temporal calibration: The 45-degree chart shows fit across both space and time simultaneously. Points cluster tightly? Good overall calibration. Wide spread? Could be spatial bias (wrong K distribution), temporal bias (wrong storage), or both. The Observation Trend Chart helps disaggregate: if the trend direction is right but magnitudes are off, the issue is likely spatial properties, not temporal response.

Export capabilities: The Post-Analysis tool can export the simulated water table as a TIFF file (for GIS integration) or save cross-section profiles (for reports). This bridges the modeling environment to other workflows — GIS analysis, regulatory submissions, client presentations.

3What's Next

With post-analysis tools mastered, continue the learning path:

Tutorial 15: Stochastic Flow Model — generate random heterogeneity and analyze uncertainty
Tutorial 16: Monte Carlo Flow Simulation — run hundreds of realizations and accumulate statistics
Tutorial 19: Automatic Parameter Estimation — let the optimizer calibrate your model systematically