Using Semantic Web Technologies to Improve Accessibility to SDIs

In this paper we will focus on the use of semantic web technologies to support easy, user-oriented access to SDIs, and on the specific issues that occur because of the spatial nature of data. A key-register for the soil and subsurface domain is being set up to provide access to soil and subsurface data to users with a wide variety in background and an equal large variety in vocabularies. The data models the data is stored in are defined in professional terminology. An infrastructure was designed and developed, that provides a semantic shell on top of an OpenGIS based spatial data store for soil and subsurface information. A first version of a web application (BRON portal) has been developed to support (end) users to pose a query related to the soil and subsurface domain in the language of their own specific domain (e.g. environment, agriculture, hydrology) and to their level of expertise (e.g. professionals, policy-makers, inexperienced). The semantic shell translates user questions to the underlying datasets terminology with the use of a domain ontology and relevant information is retrieved from a catalogue. The relevance of the retrieved information can be evaluated by the users based on the metadata and by previewing the spatial dataset (available as a service) in a map viewer. In the future, the portal also needs to provide functionality for disclosing individual features of the datasets (as WFS). Querying these datasets by building an ontology guided query will be a challenge.