An international standard conceptual model for sharing references to hydrologic features

SummaryConcepts such as catchment, basin, watershed and river are commonly understood in many fields of discourse, but are described differently according to the focus on various aspects of the hydrology phenomenon. The effective exchange of hydrologic data containing references to hydrologic features requires standardised semantics of the concepts that allow identification of these features. Here, the scope of common approaches to information modelling of hydrologic features is examined, and is compared to the requirements for feature identification in multiple contexts. A conceptual model is presented that reconciles the underlying differences in representation of hydrologic features and levels of detail in typical datasets. By providing a stable and common referencing system for hydrologic features, the model will assist in the organization of observation and modelling of such features, and in the aggregation of generated data on a global, regional, national or basin scale.The model encompasses a number of approaches used in different contexts to identify and model hydrologic features and enforce the semantics of relationships between different levels of detail. Thus, it provides a semantic framework for common feature identifiers to be developed and embedded in individual data products, while providing the flexibility to model complex hydrological processes at fine detail. The common identifiers can be used in aggregating data generated using high-detail models of processes, and in partitioning large and complex hydrologic feature datasets into local study areas. Different local models can be applied according to the dominant hydrologic processes and the amount of hydrometric monitoring available for each region.The model is intended to form the basis for standard practices under the auspices of the World Meteorological Organization Commission for Hydrology. It is presented here to invite further testing, feedback and engagement in the process of its acceptance and implementation as an international standard for hydrologic feature identification. Based on the accepted International Organization for Standardization General Feature Model, it will be possible to realise, in a standardised way, the semantics of feature identification in tools for managing metadata documenting hydrologic datasets and products.

► A conceptual model allows hydrologic features to be identified.
► Model defines semantics to allow identifiers to be interpreted.
► The same basin features can be identified in multiple scales.
► Multiple representations of hydrology can be cross-referenced.
► Formal model under auspices of WMO.