groundwater
Enable an AI agent to recognise groundwater, assess its quantity and quality, and judge proposed abstraction, recharge, protection or remediation against evidence and constraints.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise groundwater, assess its quantity and quality, and judge proposed abstraction, recharge, protection or remediation against evidence and constraints.
Groundwater is subsurface water occupying the saturated zone of soil and rock, where all voids are filled and the water is under pressure equal to or greater than atmospheric, and from which wells and springs can be supplied.
It can be Plan and interpret groundwater sampling and level monitoring at specified depths and times.; Estimate groundwater movement, storage change and water-balance uncertainty.; Evaluate a proposed abstraction rate and schedule against drawdown, connected-water and quality consequences.; Assess a managed recharge proposal for hydraulic compatibility, water quality and recoverability.; Identify protection or remediation actions for a suspected contaminant pathway.; Define monitoring thresholds that trigger review, reduced pumping or further investigation..
Distinguishing features
Determine whether the water occupies saturated subsurface pores or fractures; below-ground location alone does not distinguish groundwater from unsaturated soil moisture.
Determine whether the subject is the water or its geological host: groundwater can move through an aquifer, while the aquifer denotes the water-bearing formation.
Distinguish groundwater occurrence from water collected inside a well or pipe; a well observation requires an intake interval and measurement context before it can characterise surrounding groundwater.
Identify where subsurface water emerges into a spring, stream or other surface feature, and record that interface rather than treating all connected water as groundwater.
Check for saturation above a local unsaturated interval before assigning perched groundwater to the deeper regional groundwater system.
Scope
+ Groundwater occurrence, saturated extent and the basis for delineating a particular body or volume.
+ Groundwater levels, hydraulic pressure, storage estimates and changes through time.
+ Recharge, discharge and subsurface movement across identified boundaries.
+ Groundwater composition, contamination and suitability for specified uses.
+ Consequences and constraints of abstraction, managed recharge and remediation.
- Aquifer geology and mechanical properties as an independently modelled geological formation.
- Unsaturated soil moisture and subsurface water vapour.
- Rivers, lakes, wetlands and springs as independently modelled surface features.
- Wells, pumps, pipelines and treatment plants as engineered assets.
- Water rights, permits and allocation agreements as legal instruments.
- Dependent organisms and ecosystems as biological entities.
Characteristics
- Delineated groundwater extent
- Three-dimensional extent linked to a coordinate reference system, delineation method, date and uncertainty. Establishes which water observations and proposed actions belong to the modelled subject.
- Groundwater occurrence
- Unconfined, confined, semiconfined, perched, mixed or unresolved, with spatial context. Supports interpretation of water levels, recharge pathways and responses to pumping.
- Hydraulic head
- Metres relative to a stated vertical datum, with observation time, intake interval and relevant density correction. Provides evidence for pressure conditions, hydraulic gradients and temporal change.
- Depth to water
- Metres below a specified measuring point or land surface, with time and pumping status. Supports access and trend assessment while distinguishing observed well levels from the water table.
- Stored groundwater volume
- Cubic metres within a defined extent, distinguishing total storage, storage change and estimated recoverable volume. Prevents total water present from being equated with water that can responsibly be abstracted.
- Recharge and discharge flux
- Cubic metres per day or millimetres per year over a specified area, with boundary, period and estimation method. Supports a water balance and evaluation of changing inputs and losses.
- Hydraulic connectivity
- Connections to other groundwater zones, surface waters or the sea, with direction, timing and evidence. Identifies where pumping, recharge or contamination may have effects beyond the immediate location.
- Water composition
- Named analytes with appropriate units, detection limits, sampling depth, date and method; include field parameters where relevant. Supports identification of chemical condition, contamination and use-specific suitability.
- Groundwater condition trend
- Rising, falling, stable, seasonally variable or unresolved for head; improving, deteriorating, stable or unresolved for specified quality indicators. Distinguishes a single observation from sustained depletion, recovery or quality change.
- Use-specific availability
- Supported, conditional, unsupported or undetermined for a named use, location, rate and period. Separates physical presence from quality, access, ecological and permission constraints.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Groundwater identity and extent Establishes which saturated subsurface water is being represented and how its boundaries are justified.
An agent must distinguish the water from its host formation and avoid combining hydraulically distinct groundwater occurrences.
Saturated occurrence
Records the evidence that water occurs in a saturated subsurface zone.
Occurrence and geological host
Identify the water-bearing interval, host relationship and evidence for confinement or perched conditions.
- What observations establish saturation in the represented pores or fractures, and over which depth interval? definition
- What evidence distinguishes unconfined, confined, semiconfined or perched groundwater at this location? provenance
Groundwater boundaries
Defines spatial limits and distinguishes physical boundaries from reporting conventions.
Delineation and hydraulic continuity
Record the rationale for treating the represented groundwater as one subject and the uncertainty at its edges.
- Which lateral and vertical limits are supported by hydraulic evidence, and which are administrative or modelling boundaries? boundary
- Where might seasonal change or pumping connect, disconnect or shift the represented groundwater extent? boundary
Head, storage and change Represents groundwater pressure, saturated thickness and changes in stored water.
Water levels and storage are related but cannot be treated as interchangeable evidence of available groundwater.
Level and pressure observations
Makes groundwater level measurements interpretable across wells, depths and dates.
Comparable hydraulic head record
Record observation conditions needed to compare groundwater heads and distinguish water-table elevation from pressure head.
- What head was observed, using which datum, intake interval and time, and was the well pumping or recovering? measurement
- Does the observation represent a water table, confined pressure or a mixed response, and are density effects relevant? definition
Storage response
Links observed changes to estimates of groundwater storage and depletion.
Storage change and recoverability
Distinguish water in storage, inferred changes and water recoverable under explicit constraints.
- What storage change is inferred over the stated extent and period, using which saturated thickness and host storage properties? measurement
- What evidence separates seasonal fluctuation from persistent depletion or recovery, and how uncertain is that interpretation? provenance
Recharge, flow and discharge Tracks how groundwater is replenished, moves and leaves the represented extent.
Actions depend on replenishment times, flow pathways and exchanges with connected waters, not merely the presence of water underground.
Groundwater water balance
Records inputs, outputs and the degree to which they explain storage change.
Replenishment and losses
Account for recharge, boundary flows, abstraction and natural discharge without double counting.
- What recharge, lateral inflow, discharge and abstraction estimates apply to the same boundary and accounting period? measurement
- How well do those estimates explain storage change, and which unmeasured flows or time lags could explain the residual? provenance
Flow paths and exchanges
Represents movement within groundwater and across interfaces with other waters.
Connectivity, direction and travel time
Identify supported flow connections and distinguish inferred pathways from observed exchanges.
- Which head gradients, tracer observations or other evidence support the inferred flow directions and travel times? provenance
- Where does groundwater exchange with streams, wetlands, adjacent groundwater or the sea, and can exchange direction reverse? boundary
Groundwater quality and transport Characterises groundwater composition and the movement or transformation of undesirable constituents.
Groundwater quantity alone cannot establish usability, and a sample from one depth or location may not represent the water affected by an action.
Composition and sampling
Connects chemical and biological observations to their sampling context.
Representative quality evidence
Record measured constituents, analytical limitations and the groundwater interval represented by each sample.
- Which constituents and field parameters were measured, at what depth and time, with which units and detection limits? measurement
- How do well construction, purging, preservation and quality controls affect whether the sample represents the target groundwater? provenance
Contaminant and salinity dynamics
Records the extent, causes and potential evolution of groundwater quality problems.
Quality change pathways
Distinguish observed quality patterns from hypotheses about sources, transport and transformation.
- What evidence delineates a contaminant plume or salinity front and distinguishes background composition from introduced contamination? boundary
- How could pumping, recharge or altered geochemical conditions change contaminant movement, mobilisation or persistence? action
Groundwater actions and limits Connects proposed uses and interventions to their consequences, permissions and operating limits.
An agent needs an explicit basis for deciding whether a particular groundwater action is supported and when that decision must be revisited.
Use and intervention feasibility
Evaluates a defined abstraction, recharge or remediation proposal.
Proposal-specific availability
Assess water availability for a stated action using hydraulic evidence, quality requirements and linked permissions.
- What location, intake or injection interval, rate, duration and intended use define the proposal, and what evidence supports its feasibility? action
- Which use-specific quality criteria, treatment needs, access rights and permissions constrain the proposal, and where are those requirements recorded? action
Connected effects and operating triggers
Evaluates consequences beyond the abstraction or recharge point and defines responses to observed change.
Impact limits and response
Link potential groundwater changes to affected receptors and evidence-based operating triggers.
- What effects are supported or plausible for neighbouring wells, spring or stream discharge, groundwater-dependent ecosystems, subsidence and saline intrusion? action
- Which monitored thresholds, observation locations and review periods trigger reduced abstraction, stopped recharge or revised remediation, and who can act? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- unconfined (phreatic) aquifer water
- confined (artesian) aquifer water
- perched groundwater
- fossil / paleowater
- brackish and saline groundwater
- karst groundwater
- alluvial / unconsolidated-aquifer groundwater
- thermal / geothermal groundwater
- Which of these kinds and varieties hold for the sense of groundwater this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q161598 - item for groundwater
- Which of these identifiers and schemes hold for the sense of groundwater this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- ISO 6107 (water quality vocabulary, ISO)
- EU Water Framework Directive 2000/60/EC and Groundwater Directive 2006/118/EC
- Which of these standards and regulation hold for the sense of groundwater this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- drinking-water supply from wells and springs
- irrigation
- industrial process water
- baseflow to rivers and wetlands
- Which of these real-world use hold for the sense of groundwater this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- water-table / potentiometric head - 0-200 m below ground (highly site-specific) - m
- Which of these typical measurements hold for the sense of groundwater this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- over-abstraction and declining water tables
- saltwater intrusion in coastal aquifers
- nitrate and other contaminant plumes
- land subsidence from compaction of aquifers
- Which of these failure modes and hazards hold for the sense of groundwater this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- US/UK 'groundwater' vs some engineering usage of 'ground water' as two words
- arid regions treat fossil groundwater as a non-renewable stock
- Which of these regional variation hold for the sense of groundwater this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- soil moisture / vadose-zone water - vadose-zone water occupies unsaturated pores above the water table; groundwater occupies the saturated zone
- Which of these neighbouring kinds and how to tell them apart hold for the sense of groundwater this model covers, and on what evidence? provenance
Sources
- Groundwater: What is Groundwater? - Core definition, saturated zone vs soil moisture, unconfined vs confined aquifers
What the second pass must settle
- Does an existing Vercy world model already own groundwater or subsurface water, requiring this registry entry to link to it?
- What instance granularity should be authoritative: a hydraulically delineated groundwater body, a management unit or a bounded water volume?
- How should the model represent saturated capillary-fringe water and transitions between perched, seasonal and regional saturation?
- What minimum spatial coverage, monitoring duration and uncertainty evidence are needed before groundwater state or action feasibility can be judged?
- Which local uses, connected receptors and jurisdiction-specific requirements must be researched before action limits can be established?