| Definitionskos:definition |
The HydroFeature module (Figure 21) provides the core concepts of a named hydrologic feature in the Named Feature, of a hydrologic complex in which the union of catchment and its common outlet is realized in several ways by a collection of hydrologic features, and of a river referencing system which allows placement of an arbitrary feature ‘along a river’ using linear referencing along a one-dimensional topological, flowpath realization. The HY_HydroFeature feature type is defined as hydrology-specific instance of the General Feature metaclass (as defined in the OGC General Feature Model, GFM), whose identity needs to be maintained and tracked through a processing chain from measurement to distribution of hydrologic information.
As an instance of the General Feature metaclass a feature type is identified by a unique identifier and typical properties. Typically, a hydrologic feature is additionally identified through names in common usage and through hydrologically significant characteristics. The HY_HydroFeature feature type is specialized into more specific feature types (Figure 23), which specify additional properties and represent particular hydrologic phenomena.Providing a standard terminology for the typical relationships between hydrologic features allows the hydrosphere to be expressed in a consistent way across multiple data products, regardless of various spatial or temporal representations. The definitions of HydroFeature feature types are rooted in the definitions documented in the WMO/UNESCO Glossary of Hydrology. They are applied regardless of their application context in respect to the Earth's surface. For the purpose of testing the applicability of the HY_Features conceptual model in the context of surface water hydrology, the definitions in this standard refer to surface water hydrology. A conceptual model capturing the specifics of features associated with the groundwater domain is developed with reference to the OGC WaterML 2: Part 4 – GroundwaterML2 standard. |
