The GS SOIL Portal
The GS SOIL community provides a centralized web access point for standardized, interoperable and INSPIRE compliant European soil information. In the GS SOIL Portal http://gssoil-portal.eu all soil related information from web pages, over databases to data catalogues will be made available and accessible. Search results will be ranked and listed in shared result lists. Spatial soil data from OGC compatible Web Mapping Services (WMS) and Web Feature Services (WFS) will be visualized in a map viewer. For all tasks within the project the GS SOIL Portal will be used as a platform for an improved access to soil data. GS SOIL Portal has been built in an iterative cycle, adopting the relevant INSPIRE Implementing Rules (Network Services and related) and on the basis of the InGrid software designed for the German Environment Information Portal (PortalU). Also general open tools and services will be provided for re-use by the project partners (data / service providers) and later technical integration of services and underlying geospatial data sets. Particular focus will be placed on mutual harvesting (CSW) with external systems. The current version of the GS SOIL Portal is already available in 13 project languages.
The product harvesting, as well as the development of so-called content-framework standards (terminology, reference material and definitions to compare soil data), are based on a substantial search for existing soil data in European countries. The result has been implemented into a catalogue of soil data existing in Europe with a specific focus on products provided through web-services.
Data quality, data management and metadata
In GS SOIL two soil data relevant metadata profiles (the first one for datasets and dataset series while the second is intended for describing a service) compliant to INSPIRE metadata and ISO standards were developed in 2010. Subsequently, metadata proposed by the GS SOIL community was delivered as reference material to the Thematic Working Group for the sections dealing with metadata and data quality in the first version of INSPIRE Annex III Data Specification on soil. INSPIRE Data Specifications contain requirements (that are legally mandated) and recommendations. On the other hand, INSPIRE Data Specifications may be hardly readable by data providers that are not aware of all underlying standards. Thus, it is complicated to get an overall picture. GS SOIL Best Practice Guidelines for creating and maintaining metadata for soil databases are intended to overcome this insufficiency.
Proposed Best Practice Guidelines are covering both - metadata and data quality aspects. This approach consists of several steps, including
- a review of the GS SOIL metadata profile with respect to newly published INSPIRE documents (e.g. Commission Regulation 1089/2010 on interoperability of spatial data sets and services or new version 1.2 of Technical Guidelines on INSPIRE metadata),
- connections between dataset metadata and feature-level metadata through a feature catalogue,
- user-friendly guidelines for data providers who would like to describe their soil-related databases,
- the GS SOIL metadata profile applied on two real soil datasets as examples,
- guidelines on how to manage soil metadata in two or more languages,
- brief information about the development of the soil specific multilingual thesaurus (which is in detail written in the following section)
- and examples on usage of soil metadata within INSPIRE, i.e. spatial data infrastructure framework (e.g. how to get from dataset metadata to view/download service or dataset itself as well as description of related aspects).
Soil specific multilingual thesaurus
Sharing metadata and/or data generally leads to the need of common semantics, a common set of concepts and a common controlled vocabulary. This is a fact well-known long before the existence of IT and IT networks, and has lead to controlled lists of physical units, chemical elements, species lists or even to complete vocabularies like the medical or pharmaceutics vocabularies. Today thesauri and/or ontologies have become state of the art within communities and international projects even when the participants do not want to share data but "just" want to exchange their knowledge. Public institutions who collect data/information/knowledge from various parties meet this well-known need establishing controlled vocabulary and making it accessible for their data providers. The European Environmental Agency e.g. uses and publishes GEMET, the GEneral Multilingual Environmental Thesaurus, Which is provided in 26 languages, as multilingualism is a need for any European collaboration, not only in the environmental sector. Referencing concepts of GEMET is requested by the EU INSPIRE directive.
As GS SOIL aims to be INSPIRE compliant, GEMET has to be at least a part of the controlled vocabulary of that project. But GEMET represents a very general environmental vocabulary and needs more specific extensions for special domains, such as water, protected areas, air and - soil.
The GS SOIL Portal has a reference to a service for GEMET but for the reasons explained above, in addition to the preliminarily planned tasks, the GS SOIL community decided to establish a soil specific multilingual thesaurus in addition to the preliminarily planned tasks.
Application schema, data harmonization and interoperability
The application schema extended in GS SOIL and its implementation serve as reference material for the INSPIRE process of data specification development (e.g. proposal for a soil metadata profile). The GS SOIL amendments to the former ISO 28258 Working Draft were fed back into the ISO process. The application schema is tested with data from the GS SOIL data providing partners using a hands-on testing procedure description. The GS SOIL SoilML is compared with the currently developed INSPIRE application schema for soil data.