OneGeology-Europe - the first step to the European Geological SDI
A. Tellez-Arenas1, R.Tomas2, J. Laxton3, J.J.Serrano1
1BRGM, French Geological Survey, Orléans, France,
2Czech Geological Survey, Prague, Czech Republic,
3British Geological Survey, Edinburgh, UK,
OneGeology-Europe is a large ambitious project to make geological spatial data
further known and accessible. The OneGeology-Europe project develops an integrated
system of data to create and make accessible for the first time through the internet the
geological map of the whole of Europe. Moreover the portal will become a single
point of access for the discovery and evaluation of multilingual information about the
national geological and applied geological datasets at all scales from 26 European
countries. The architecture implemented by the project is web services oriented, based
on the OGC standards: the geological map is not a centralized database but is
composed of several web services, each of them hosted by a European country
involved in the project.
Since geological data are structured differently from country to country, they are
difficult to share. OneGeology-Europe, while providing more detailed and complete
information, will also enable an easier exchange of data beyond the geological
community, within Europe and globally. OneGeology-Europe is characterised by the
high technological capacity of the EU Member States, and has the final goal of
achieving the harmonisation of European geological survey data according to
common standards. As a direct consequence Europe will make a further step in terms
of innovation and information dissemination, continuing to play a world leading role
in the development of geosciences information.
The technical team has defined an architecture with the following main components: a
common data model to exchange geological data; the mapping of geological data by
each data provider to the common data model; a set of web services to view, access,
and process the geological data; a metadata repository - catalogue, with its metadata
editor, to register metadata of datasets and services; and a geoportal to provide a userfriendly way to discover, view and access geological data.
In order to give a user enough information about the national geological and applied
map datasets a Multilingual Geological Metadata Profile based on ISO standards (ISO
19115/19119, and 19139 for XML encoding) is defined. This profile takes into
account (is fully in compliant with) INSPIRE Implementing Rules for metadata. In
addition a specific set of metadata elements related mainly to data quality have been
selected from the ISO 19115 metadata catalogue. The profile also includes metadata
elements for services.
To manage these metadata, and to enable the searching of references to available
geological datasets and services, a Catalogue Service has been set up, based on the
OGC standard (CSW – Catalogue Service for the Web, with an ISO Application
Profile). This service is as much as possible compliant with INSPIRE Implementing
Rules defined for the discovery service. The OneGeology Portal uses this CSW
interface to access the catalogue. The metadata catalogue will be provided in 16
European languages, with the possibility of extending to other languages.
The data model is based on GeoSciML, developed since 2006 by a group of
Geological Surveys. GeoSciML is already compliant with many INSPIRE rules
defined for data specification. The data providers involved in the project implemented
a new component that allows the web services to deliver the geological map expressed
in GeoSciML. Furthermore, Geological data held by national geological surveys are
generally described in the national language of the country. The project has to deal
with the multilingual issue, an important requirement of the INSPIRE directive. The
project provides a list of harmonised vocabularies, a set of web services to deal with
them, and a web site to help geoscientists to map from the terms used in the national
datasets to those in the harmonised vocabularies.
The web services provided by each data provider, with the particular component that
allows them to deliver the harmonised data model and to handle multilingualism, are
the first part of the architecture. OneGeology-Europe view and download services are
compliant with the Implementing Rules for services, and their implementation is very
close to the recommendations provided by the Technical Guidance documents.
The project also implements a web portal that provides several functions. Thanks to
the common data model implemented by each web service delivering a part of the
geological map, and using OGC SLD standards, the client application offers the
following option: a user can request a sub-selection of the map, for instance searching
on a particular attribute such as “age is quaternary”, and display only the parts of the
map based on this filter. Using the web services for the harmonised vocabularies the
data displayed are translated.
The project started in September 2008 with a duration of two years, with 29 partners
from 20 countries (20 partners are Geological Surveys). The budget is 3.25 M€, with a
European Commission contribution of 2.6 M€. The presentation will describe the
technical solutions to implement OneGeology-Europe components: the metadata
profile, the profile of the common data model to exchange geological data, the web
services to discover, view and access geological data; and a geoportal to provide the
user with a user-friendly way to discover, view and access geological data.