Appendix J: Still More Ecosystem Services with InVEST

1 Purpose of this appendix

Across Appendices G–I, you have seen how InVEST represents:

  • production (crops, timber, fisheries),
  • regulation (water, floods, heat, coasts, sediment),
  • carbon,
  • habitat and biodiversity,
  • recreation and culture,
  • and energy siting.

This appendix completes the InVEST landscape by introducing models that focus on:

  • seasonality and water security,
  • groundwater and long-run hydrology,
  • urban access and equity,
  • visual and cultural value, and
  • coastal blue carbon systems.

These services are especially important for Earth–economy modeling because they:

  • operate on slow timescales,
  • shape human well-being directly,
  • and mediate climate adaptation.

2 Seasonal water yield

The Seasonal Water Yield (SWY) model extends the annual water-yield logic to capture:

  • how water is partitioned across seasons,
  • how much becomes quick runoff,
  • and how much becomes baseflow that sustains rivers in dry periods.

Inputs:

  • precipitation by season,
  • evapotranspiration,
  • soils,
  • land cover,
  • topography.

Conceptually:

Quickflow = f(Rain, Imperviousness, Soil) Recharge = f(Rain, Vegetation, Soil) DrySeasonFlow ≈ AccumulatedRecharge

Outputs:

  • maps of baseflow contribution,
  • seasonal runoff,
  • watershed-level water security metrics.

Earth–economy use:

  • evaluate how deforestation alters dry-season water,
  • link land use to hydropower reliability,
  • connect watershed protection to urban water supply,
  • embed seasonality into economic risk.

This turns forests into intertemporal water infrastructure.

3 Groundwater recharge and managed aquifers

Closely related, InVEST supports analysis of:

  • natural groundwater recharge,
  • and the potential for managed aquifer recharge (MAR).

These models estimate:

  • where infiltration occurs,
  • how land cover affects percolation,
  • and where recharge investments are most effective.

Conceptually:

Recharge = f(Soil, Slope, Vegetation, Rain) AquiferStock_{t+1} = AquiferStock_t + Recharge − Extraction

Outputs:

  • recharge maps,
  • priority zones for protection or investment,
  • long-run water balance implications.

Earth–economy use:

  • connect land policy to water scarcity,
  • represent aquifers as stocks,
  • evaluate drought resilience,
  • integrate water security into inclusive wealth.

Aquifers become hidden capital accounts.

4 Urban nature access

The Urban Nature Access model estimates:

  • how easily people can reach green space,
  • given distance, barriers, and population density,
  • and how access changes under development scenarios.

Inputs:

  • green space maps,
  • street networks,
  • population distribution,
  • travel thresholds.

Conceptually:

Access = f(Distance, Connectivity, Population)

Outputs:

  • maps of population served by green space,
  • equity metrics by neighborhood,
  • changes under land-use plans.

Earth–economy use:

  • connect urban form to well-being,
  • evaluate green infrastructure equity,
  • treat access as a social stock,
  • link planning to health outcomes.

This model makes who benefits spatially explicit.

5 Scenic quality

The Scenic Quality model estimates:

  • how visually intrusive features (roads, mines, towers) affect landscapes,
  • who sees them,
  • and how far their visual influence extends.

Inputs:

  • digital elevation models,
  • land cover,
  • locations of visual disturbances,
  • viewer locations.

Conceptually:

VisualImpact = f(Visibility, Distance, Contrast) ScenicQuality = Baseline − VisualImpact

Outputs:

  • maps of visual degradation,
  • counts of people affected,
  • scenario comparisons.

Earth–economy use:

  • integrate aesthetics into land planning,
  • evaluate infrastructure siting,
  • connect landscape change to tourism and identity,
  • formalize cultural services.

This turns “sense of place” into a system variable.

6 Coastal blue carbon

The Coastal Blue Carbon model estimates:

  • carbon stored in mangroves, marshes, and seagrass,
  • emissions from degradation,
  • sequestration from restoration.

Inputs:

  • habitat maps,
  • carbon pool parameters,
  • transition scenarios.

Conceptually:

C_total = C_biomass + C_soil ΔC = C_future − C_current

Outputs:

  • coastal carbon stocks,
  • avoided emissions,
  • mitigation potential.

Earth–economy use:

  • integrate coastal ecosystems into climate policy,
  • value restoration as mitigation,
  • link sea-level rise to asset loss,
  • treat wetlands as climate capital.

Here, shorelines become carbon infrastructure.

7 Why these services matter

These models share three properties that are central to Earth–economy thinking:

  1. They are stock-based.
    • Aquifers, baseflow, access, scenic quality, blue carbon
      all accumulate or erode over time.
  2. They are spatially unequal.
    • Benefits and losses fall on specific communities.
  3. They mediate resilience.
    • Drought survival, heat stress, flood recovery, identity.

They therefore connect directly to:

  • inclusive wealth,
  • intergenerational equity,
  • and robustness under uncertainty.

8 From hidden services to explicit systems

Consider this chain:

Urban expansion → Loss of wetlands and trees → ↓ Blue carbon, ↓ cooling, ↓ recharge → ↑ Heat exposure, ↑ flood risk, ↓ water security → ↑ Health costs, ↓ productivity → Changed wages, rents, and migration → New land-use equilibrium

Without InVEST-style services, this chain is invisible.

With them, it becomes:

  • computable,
  • testable,
  • and designable.

9 Exercises

  1. Equity lens.
    Choose one of the services in this appendix.
    Describe how it could widen or narrow inequality across neighborhoods.

  2. Stock mapping.
    For seasonal water yield or groundwater, identify:

    • the stock,
    • the inflows,
    • the outflows,
    • one policy lever.

  3. Coupled future.
    Sketch how coastal blue carbon could be integrated into:

    • a national climate plan,
    • and an Earth–economy model.

With Appendices G–J, InVEST appears not as a toolkit of niche models,
but as a catalog of ecological production functions.

Earth–economy modeling is what happens
when every one of those functions
is allowed to reshape the economy.