Choose your path
- Everyone starts with the Universal Starter Path (§27.1) — the common foundation. 4-6 hours of reading plus tutorial work. After this, you can build basic models.
- Graduate student learning groundwater modeling: Universal Starter → Academic path (§27.2). Build up through Parts II and III chapter by chapter.
- Teaching faculty using IGW-NET in classroom: Universal Starter → Teaching Faculty path (§27.3). Focus on chapters with strong teaching value and built-in conceptual hooks.
- Consulting professional: Universal Starter → one of three professional tracks in §27.4 — Contamination Investigation, Water-Supply Planning, or Regulatory Review.
- Researcher / method-developer: Universal Starter → Research path (§27.5). Stochastic modeling, calibration, advanced features.
- Switching from MODFLOW or GMS: Universal Starter + Platform-Switcher path (§27.6). Covers where IGW-NET differs from traditional workflows.
27.1 The Universal Starter Path — Everyone Reads This
Regardless of your role, start here. The Universal Starter covers the conceptual foundation and the baseline workflow — what IGW-NET is, how the interface is organized, and how to build-simulate-interpret a model from end to end. After completing this path, you can build simple models; you then branch into a specialty path based on your goals.
27.1.1 The sequence
| Step | Chapter / Resource | Why |
|---|---|---|
| 1 | Ch. 1 — What IGW-NET Is | The conceptual framework. xyz vs ijk (Conceptual vs Numerical), hierarchy, the Global Base Model philosophy. Without this context, individual features don't cohere. |
| 2 | Ch. 2 — Navigation and Interface | The four-tier tool organization; how dialogs work; map interaction. Prepares you for everything else. |
| 3 | Ch. 3 — Your First Model | A complete end-to-end walkthrough. By the end, you've built, simulated, and viewed a model. |
| 4 | Tutorial 1 — Steady 2D Flow | Hands-on reinforcement of Ch. 3. Working through this locks in the basic workflow. |
| 5 | Ch. 4 — Domain Definition | How to size and place your model; the Global Base Model provides context even before you customize. |
| 6 | Ch. 5 — Aquifer Attributes | The central chapter on properties. K, recharge, elevations, storage. Where most of the physics lives. |
| 7 | Ch. 7 — Running the Simulation | Solver basics, NX warnings, water-table-as-top. (Ch. 6 features and Ch. 9 transient can wait unless you need them immediately.) |
| 8 | Ch. 8 — Viewing Results | How to interpret what the simulation produces. Mass balance, head fields, contour lines. |
Time estimate: 4-6 hours total, including Tutorial 1. After this, you can build simple, well-bounded models.
27.1.2 What you can skip initially
The Universal Starter deliberately skips Ch. 6 (Adding Features beyond the minimum) and Ch. 9 (Transient). Both are essential for serious work but add complexity that isn't needed for a first model. Once the starter path is complete, most specialty paths bring these chapters back in.
27.2 Academic Path — The Graduate Student
For graduate students learning groundwater modeling as part of coursework or thesis research. Goal: build conceptual understanding alongside practical competence, preparing for independent modeling work.
27.2.1 After the Universal Starter
The graduate student should build up Parts II and III chapter by chapter. Take time with each; consider tutorials that match each chapter's topic.
| Phase | Chapters | Tutorials | Purpose |
|---|---|---|---|
| Phase 1 — Complete Parts I-II | Ch. 6, Ch. 9 | Tutorial 7 (Transient) | Round out the basics you skipped in the starter |
| Phase 2 — Particle tracking and transport | Ch. 11, Ch. 12 | Tutorial 3 (Particle Tracking), Tutorial 5 (Transport) | The two most important analyses beyond steady flow |
| Phase 3 — Advanced structure | Ch. 10 (Layering), Ch. 13 (Nesting), Ch. 14 (SW as BC) | Tutorial 2 (Nested Modeling), Tutorial 10 (Aquifer Layers) | Multi-scale and multi-layer modeling |
| Phase 4 — Heterogeneity and calibration | Ch. 17 (T-PROGS), Ch. 18 (Calibration) | Tutorial 24 (T-PROGS), Tutorial 8 (Calibration), Tutorial 19 (Auto-Calibration) | Real aquifers are heterogeneous; real models are calibrated |
| Phase 5 — Uncertainty | Ch. 19 (Stochastic) | Tutorials 15-18 (all four stochastic tutorials) | Probabilistic thinking; contemporary uncertainty methods |
27.2.2 Case studies to read
- Mancelona TCE plume — after completing Phase 2 (transport)
- Barron Lake coupled model — after Phase 3 (surface water)
Total time estimate: 40-60 hours spread across a semester or equivalent. A dedicated student could compress to 2-3 weeks of full-time study.
27.2.3 What can wait
Ch. 15 (Coupled Lakes) and Ch. 16 (Watershed) can be deferred unless the student's research directly touches them. Part IV reference catalogs (Ch. 21-25) are lookup references; read them only when you need the specific content.
27.3 Teaching Faculty Path — Using IGW-NET in the Classroom
For faculty who teach groundwater modeling and want to use IGW-NET as a platform. Goal: build a classroom curriculum that leverages the platform's real-time, interactive nature while covering essential groundwater concepts. Synthetic mode (Ch. 1 §1.3.2) is the faculty-path workhorse — the blank canvas functions as a blackboard with live physics attached. You sketch a concept in front of students, the simulation responds immediately, and the class sees the relationship between assumption and outcome in real time. Many of the most effective teaching demonstrations below are done in synthetic mode before moving to georeferenced examples later in the course.
27.3.1 A 14-week course sequence
| Week | Topic / Chapter | Tutorial / Activity |
|---|---|---|
| 1-2 | Ch. 1 — What IGW-NET Is; conceptual framework (xyz vs ijk, hierarchy, Global Base Model) | Tutorial 1 in-class demonstration; students build first model |
| 3-4 | Ch. 4 domain, Ch. 5 aquifer attributes, Ch. 6 features | Tutorial 9 (Synthetic Model) — excellent for controlled teaching |
| 5-6 | Ch. 7 simulation (NX warnings, water-table-as-top), Ch. 8 results interpretation | Assign first student-built model with critique |
| 7 | Ch. 9 transient modeling — the first major analytic extension | Tutorial 7 (Transient) |
| 8 | Ch. 11 particle tracking — the visualization that makes flow intuitive | Tutorial 3 (Particle Tracking) |
| 9 | Ch. 12 transport — contamination problems begin | Tutorial 5 (Contaminant Transport); introduce Mancelona case study |
| 10 | Ch. 13 nested modeling — the hierarchy concept made concrete | Tutorial 2 (Nested Modeling); 10-cell buffer rule demonstration |
| 11 | Ch. 14 surface water as BC — the three levels; DEM-as-drain concept | Tutorial on SW integration; introduce Barron Lake case study |
| 12 | Ch. 17 T-PROGS — heterogeneity as reality | Tutorial 24 (T-PROGS 3D Geologic Model) |
| 13 | Ch. 18 calibration — structure-first principle | Tutorial 8 (Calibration); discussion of non-uniqueness |
| 14 | Ch. 19 stochastic modeling — contemporary uncertainty methods | Tutorial 16 (Monte Carlo Flow); recursive-statistics discussion |
27.3.2 Teaching-strength chapters
Certain chapters are especially valuable in the classroom because of built-in conceptual hooks:
- Ch. 1 §1.5 (xyz vs ijk) — the fundamental distinction between conceptual and numerical models
- Ch. 7 (water-table-as-top) — the linearize-within / iterate-between scheme is a clear nonlinear-PDE teaching example
- Ch. 13 (nested modeling, 10-cell buffer rule) — concrete computational hierarchy; good for exam-style problems
- Ch. 14 (three levels of SW representation) — progressive complexity framework that generalizes beyond SW
- Ch. 17 (AQ/MAQ/PCM/CM typology, four-scalar-K) — rigorous but accessible framework for heterogeneity
- Ch. 18 §18.1.3 (structure-first, calibration-second) — a principle that generalizes across all modeling
- Ch. 19 (recursive statistics) — contemporary research method not in most textbooks
27.3.3 Using case studies
Both case studies work well as semester projects:
- Mancelona TCE — combines transport (Ch. 12), T-PROGS (Ch. 17), calibration (Ch. 18), and stochastic (Ch. 19). Rich enough for a full-semester project.
- Barron Lake — SW-GW coupling (Ch. 14-15). Smaller scope; good mid-course project.
27.4 Professional Paths — Contamination, Water Supply, Regulatory
Three professional paths for different consulting and regulatory roles. Each builds on the Universal Starter and adds specialty chapters.
27.4.1 Contamination investigation consultant
Goal: analyze a contaminated site, characterize plume behavior, design remediation, defend conclusions to regulators.
| Phase | Chapters | Tutorials | Rationale |
|---|---|---|---|
| 1 | Ch. 6 features, Ch. 9 transient | Tutorial 7 | Round out starter path; transient is essential for transport |
| 2 | Ch. 11 particle tracking, Ch. 12 transport | Tutorial 3, Tutorial 5, Tutorial 17 (MC Transport) | Core contamination analyses |
| 3 | Ch. 17 T-PROGS | Tutorial 24 | Heterogeneity dominates contaminant behavior; T-PROGS is essential |
| 4 | Ch. 18 calibration | Tutorial 8, Tutorial 19 | Calibrate against observed contamination |
| 5 | Ch. 19 stochastic | Tutorials 15, 16, 17, 18 | Risk quantification; probabilistic capture zones |
| 6 | Case study: Mancelona TCE | — | End-to-end worked example |
Time estimate: 20-30 hours on top of the starter.
27.4.2 Water-supply planner
Goal: design well fields, protect source-water quality, manage long-term sustainability.
| Phase | Chapters | Tutorials | Rationale |
|---|---|---|---|
| 1 | Ch. 6 features, Ch. 9 transient | Tutorial 7, Tutorial 20 (Theis) | Pumping wells, drawdown analysis |
| 2 | Ch. 11 particle tracking (backward) | Tutorial 3 | Capture zone delineation for wellhead protection |
| 3 | Ch. 14 surface water, Ch. 15 coupled lakes | — | Most water-supply wells depend on SW-GW interactions |
| 4 | Ch. 18 calibration | Tutorial 8 | Calibrate against observed SWLs at monitoring wells |
| 5 | Ch. 19 stochastic (probabilistic capture zones) | Tutorial 18 (Probabilistic Capture) | Risk-based wellhead protection zones |
| 6 | Case study: Barron Lake (if lake-adjacent supply) | — | SW-GW interaction worked example |
Time estimate: 15-25 hours on top of the starter.
27.4.3 Regulatory reviewer
Goal: review models submitted by others, assess adequacy, identify problems, make regulatory decisions.
| Phase | Chapters | Rationale |
|---|---|---|
| 1 | Ch. 18 §18.1.3 (structure-first) and §18.8 (non-uniqueness) | The single most important review concept — look for structural soundness, not just numerical fit |
| 2 | Ch. 25 (Error Messages and Diagnostics) — §25.5.2 especially | "Good heads, wrong flow" — the signature of structural error hiding behind calibration |
| 3 | Ch. 22 (Field Reference) | Understand what fields a model file actually stores |
| 4 | Ch. 19 §19.8.3 (parameter vs structural uncertainty) | Monte Carlo confidence intervals on a flawed structure are misleading; understand the distinction |
| 5 | Ch. 20 (MODFLOW Integration) | Understand what's the native IGW solver vs USGS engines; assess when MODFLOW export would add rigor |
| 6 | Ch. 14 §14.7 (10×-rainfall pitfall) | A common unit-error failure mode to watch for |
Time estimate: 8-12 hours on top of the starter. Regulators need depth in specific areas (calibration, uncertainty, common failure modes) more than breadth across all features.
27.5 Research Path — Methods and Uncertainty
For researchers developing methods, pushing the platform's capabilities, or doing uncertainty-focused work. Goal: deep understanding of advanced features and the parser-backed foundation.
27.5.1 The research sequence
| Phase | Chapters | Tutorials |
|---|---|---|
| 1 — Core | All of Parts I-II (the starter + Ch. 6, 9) | Tutorials 1, 3, 5, 7 |
| 2 — Heterogeneity and uncertainty | Ch. 11 particles, Ch. 12 transport, Ch. 17 T-PROGS, Ch. 19 stochastic | Tutorials 15-19, 24 |
| 3 — Calibration and inversion | Ch. 18 calibration (all sections, especially §18.7 UCODE and §18.8 non-uniqueness) | Tutorials 8, 19, 28 (Data Processing Regression) |
| 4 — Multi-engine and export | Ch. 20 MODFLOW Integration | Tutorial 23 (MODFLOW Analysis Tool) |
| 5 — Platform Reference | Ch. 22 Common Pitfalls + the full Platform Reference pillar | — |
| 6 — The parser itself | Inspect igw_net_parser_v3.py directly for ground-truth model-file semantics | — |
27.5.2 High-value deep-dive topics
- Ch. 19 §19.6 — recursive-statistics architecture. Contemporary method for 2D/3D ensemble statistics without ensemble storage. Publishable topic in its own right.
- Ch. 18 §18.8 — K-recharge non-uniqueness. Fundamental inverse-problem concept; multi-target calibration as the resolution.
- Ch. 17 §17.5 — regional zonation with 4N parameters. Data-driven zonation principle.
- Ch. 13 — nested modeling and hierarchy. The computational hierarchy as a unifying framework that generalizes beyond groundwater.
Time estimate: 60-80 hours of focused study; typically spread across multiple projects as specific features become relevant.
27.6 Platform-Switcher Path — Coming from MODFLOW, GMS, or Similar
For experienced modelers already comfortable with MODFLOW, Groundwater Vistas, GMS, or similar platforms. Goal: understand where IGW-NET differs from traditional workflows and where to go for specific capabilities you already know.
27.6.1 The differences that matter
| What you know from traditional platforms | IGW-NET difference | Chapter to read |
|---|---|---|
| Build model in GUI, run MODFLOW, view results — a batch workflow | IGW-NET is real-time interactive; results stream as the solver runs | Ch. 1 §1.3; Ch. 7 |
| Choose MODFLOW variant explicitly | IGW-NET selects automatically; native IGW solver for structured grids, MF6 DISV for unstructured | Ch. 20 |
| Compile DEM, K, recharge from external sources | Data Center provides curated defaults (Global Base Model); refine progressively rather than build from scratch | Ch. 1 §1.4; Ch. 23 |
| Explicit "enable transport" toggle | Transport activates automatically when concentration sources exist | Ch. 12; Ch. 21 §21.3.1 |
| Build layered model explicitly | Sublayers vs layers distinction; water-table-as-top linearize-within/iterate-between | Ch. 7 §7.4.3, Ch. 10 |
| Manual BC setup for every stream | Streams and lakes auto-load from Global Database; three-level progressive representation | Ch. 14 |
| Calibrate with PEST or UCODE externally | UCODE integrated; Automatic Calibration is a Calib checkbox workflow | Ch. 18 |
| Batch Monte Carlo with ensemble post-processing | Recursive ensemble statistics — compute-render-discard without ensemble storage | Ch. 19 §19.6 |
27.6.2 Reading sequence for switchers
| Step | Chapter | Why |
|---|---|---|
| 1 | Ch. 1 (full read, especially the conceptual framework) | Different mental model than traditional platforms |
| 2 | Universal Starter steps 2-8 | Rapid orientation to the platform's specifics |
| 3 | Ch. 20 (MODFLOW Integration) | Ground yourself in how the familiar engines map to IGW-NET features |
| 4 | Ch. 13 (nested modeling) | Hierarchical modeling is more central in IGW-NET than most other platforms |
| 5 | Ch. 19 (stochastic) | The recursive-statistics pattern is unfamiliar to most MODFLOW users |
| 6 | Ch. 25 (Error Messages) — especially §25.5.2 | Diagnostic patterns you'll use for troubleshooting |
Time estimate: 12-18 hours. Switchers already know groundwater modeling; they need to learn IGW-NET's specifics, not the underlying physics.
27.6.3 Key mental adjustments
Experienced modelers often start by clearing everything and building up. In IGW-NET, this works against the platform. The Global Base Model + Data Center defaults give you a working starting point; refine progressively rather than build from zero. The "accept defaults, then refine" workflow is central. See Ch. 1 §1.4 and Ch. 5 §5.1.2.
Traditional workflow: pick your MODFLOW variant, configure it, run it. IGW-NET workflow: configure the conceptual model; the platform picks the right engine automatically based on model features. Override only when you have a specific reason. See Ch. 20 §20.1.
Most platforms treat sub-regional detail as a telescoping post-process or a grid refinement. IGW-NET treats nesting as a first-class structural pattern (Ch. 13). Use it deliberately — a parent regional model plus a refined submodel is cleaner than a single model trying to resolve both scales. See Ch. 13.
Related references
- Chapter 28 — Glossary → — next chapter. Terminology reference.
- Chapter 29 — Collaborative Workflows — Observatory integration and Global Model Network publishing.
- Chapter 26 — Help Resources — the documentation ecosystem map.
- Quick Tutorials index — 28 step-by-step walkthroughs.
- Case Studies — Mancelona and Barron Lake.
- Concept Pages — cross-cutting conceptual explanations.