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NADM North American Geological Data Model
OGC Open Geospatial Consortium
OM OGC Observations and Measurements Conceptual Model
OMXML Observations and Measurements XML Implementation
SensorML Sensor Model Language
SOS Sensor Observation Service
SWE Sensor Web Enablement
UML Unified Modeling Language
UTC Coordinated Universal Time
URI Universal Resource Identifier
URL Universal Resource Locator
WML2 WaterML 2.0 – Part 1
XML Extensible Markup Language
XSD W3C XML Schema Definition Language
5.7 UML notation
The diagrams that appear in this specification, including the GWML2 Conceptual and Logical schemas, are presented using the Unified Modeling Language UML, in
compliance with ISOIEC 19505-2.
Note: Within the GWML2 conceptual and logical diagrams, the following color scheme is used to identify packages, except where noted i.e. Figure 16. This is just for
information purposes.
Amber: GWML2 defined within this specification Green and
Purple : from GeoSciML
Blue: from OM
5.8 Finding requirements and recommendations
This specification is identified as http:www.opengis.netspecgroundwaterml2.1
. For clarity, each normative statement in this specification is in one and only one place and
defined within a requirements class table and identified with a URI, whose root is the specification URI. In this specification, all requirements are associated to tests in the
abstract test suite in Annex A. using the URL of the requirement as the reference
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identifier. Recommendations are not tested but are assigned URLs and are identified using the ‘Recommendation’ label in the associated requirements table.
Requirements classes are separated into their own clauses, named, and specified according to inheritance direct dependencies. The Conformance test classes in the test
suite are similarly named to establish an explicit and mnemonic link between requirements classes and conformance test classes.
6. Background
6.1 Technical Basis
This specification builds on a number of standards for encoding XML data, including: OMXML OGC 10-025r1
sweCommon OGC 08-094r1 GML ISO 19136:2007 OGC 07-036
ISO 19139 Metadata W3C XSD
This specification also builds on existing schema, primarily Observations Measurements OMXML and GeoSciML 3.2. It accomplishes this by a extending
these schemas with groundwater specializations, b referring to a class in these schema in order to type a named property, or c using a class from the schemas as one of the two
participants in a binary relationship.
6.2 Overview of Observations Measurements
ISO19156 – Observations and Measurements is a generic GML schema for observations. As shown in Figure 1, it defines an observation as “…an act associated with a discrete
time instant or period through which a number, term or other symbol is assigned to a phenomenon. It involves application of a specified procedure, such as a sensor,
instrument, algorithm or process chain. The procedure may be applied in-situ, remotely, or ex-situ with respect to the sampling location. The result of an observation is an
estimate of the value of a property of some feature.”
6.3 Sampling features
Sampling features in OM are defined as a “feature, such as a station, transect, section or specimen, which is involved in making observations concerning a domain feature.”
Sampling features in the groundwater domain are features along which, or upon, observations are made. The most relevant are water wells and boreholes, which
effectively host observations along staged intervals; a collection of these intervals and their observations constitutes a log.
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Figure 1: Observation in OM.
6.4 Overview of GeoSciML 3.2
