HydrogeoUnit

What is an HydrogeoUnit?

These are distinct volumes of earth material that serve as containers for subsurface fluids. The boundaries of a unit are typically discriminated from those of another unit using properties related to the potential or actual ability to contain or move water. The properties can be geological or hydraulic, and typically include influences from the surrounding hydrological environment. More specifically, the conceptual model delineates two types of hydrogeological units, with slightly different orientations: aquifer-related units have boundaries delimited by the hydrogeological properties of the rock body, while groundwater basins have boundaries delimited by distinct flow regimes. Aquifer-related units are subdivided into aquifer systems, which are collections of aquifers, confining beds, and other aquifer systems. Confining beds are units that impede water flow to surrounding units, and supersede notions such as aquitards, aquicludes, and aquifuges, which are not included herein, as it is difficult to differentiate these in practice.

Realizations

Data model	Concept name	Definition
OGC GWML2	HydrogeoUnit	Any soil or rock unit or zone that by virtue of its hydraulic properties has a distinct influence on the storage or movement of groundwater.
IFC	HydrogeoUnit	Same as OGC GWML2
AGSi	agsiModelElement	In AGSi a model is collection of elements (agsiModelElement object) and this may include hydrogeological units, identified as such using the elementType attribute.

Properties

Inherited properties from the GeologicUnit concept

See GeologicUnit

Specific properties

PropertyName	Definition
Identifier	Globally unique identifier shall uniquely identifies a tuple within the dataset and be formatted as an absolute URI conformant to RFC 3986.
Name	name contains a display name for the HydroGeoUnit.
gwUnitDescription	Description of the unit.
gwUnitMetadata	Metadata for the unit .
gwUnitName	Name of the unit (common local name or formal name).
gwUnitThickness	Typical thickness of the unit.
gwUnitMedia	Type of material or, by proximity, type of voids (e.g., granular, fracture, karstic, or mixed).
gwUnitRecharge	Volumetric flow rate of water that enters an hydrogeologic unit, at potentially multiple locations.
gwUnitDischarge	Volumetric flow rate of water that goes out of an hydrogeologic unit, at potentially multiple locations.
gwUnitWaterBudget	Sum of water input and output of a hydrogeologic unit, at a particular point in time, with a description of inflows and outflows.
gwUnitVulnerability	The susceptibility of the aquifer to specific threats such as various physical events (earthquakes), human processes (depletion), etc.
gwUnitShape	The geometry of the unit.
LinkToAnObservationAPI
PermeabilityHoz	value of horizontal permeability
Permeabilityvert	value of vertical permeability
Transmissivity	Parameter governing the flow of water flowing per unit width of the saturated zone of a continuous aquifer (measured in a direction orthogonal to that of flow), and per unit of hydraulic gradient
Storage coefficient	Ratio of the volume of water released or stored per unit area of an aquifer, to the corresponding charge in hydraulic head, without reference to time
Specific storage	Volume of water released or stored per unit area of an aquifer, to the corresponding charge in hydraulic head, without reference to time
EffectivePorosity	Ratio of the volume of gravitational water that a medium porous may contain in a state of saturation then release under the effect of complete drainage (laboratory drainage on a sample), to its total volume
IntrinsicPermeabilityDirection	direction of intrinsic permeability
IntrinsicPermeabilityValue	value of intrinsic permeability
HydraulicFlowVelocity	Fictitious macroscopic speed of a water flow in uniform movement through a saturated aquifer medium (speed vector of Darcy's law) deduced from the flow rate referred to the total section of the aquifer crossed by the flow
InitialWaterSaturation	In situ state, initial water saturation level (before construction)

FAQ

GitHub issue

https://github.com/opengeospatial/Geotech/issues/13