The 1 : 5 Million International Geological Map of Europe and Adjacent Areas
- Introduction and Setting
- Cooperation with International Participants and Scientific Advisors
- Setting Standards for the Analogue and Digital Data Preparation
- Data Harmonisation and Synthesis
- Copyright and Data Dissemination
- References
Introduction and Setting
A major European GIS project: the 1:5 Million International Geological Map of Europe and Adjacent Areas (IGME 5000) was managed and implemented by the Federal Institute for Geosciences and Natural Resources (BGR) under the aegis of the CGMW (Commission of the Geological Map of the World). The project involved over 40 European and adjacent countries and the area covered reaches from the Caspian Sea in the east, to the Mid-Ocean Ridge in the west, and from Svalbard to the southern shore of the Mediterranean Sea. The aims of the project were to develop a GIS underpinned by a geological database, and also a printed map providing up-to-date and consistent geological information.
The GIS is holding significantly more information than the previous printed maps could ever provide. It also offers versatility, e.g. to retrieve and present for the whole of Europe, information on age, petrography and structural and metamorphic features. More importantly the IGME 5000 GIS is providing the essential foundation for pan-European applied geo-environmental thematic mapping.
While the main theme of the GIS is the pre-Quaternary geology of both the land and offshore areas of Europe, the additional theme of the Quaternary geology of Europe (IQUAME 2500) is in the process of being compiled - a key factor influencing the natural landscape.
The project was depending on the numerous contributions of the many countries. An extensive multinational project like the IGME 5000 requires meticulous preparation and establishment of standards and protocols in order to provide the essential structure and guidelines for the data compilation, i.e. common term dictionaries for the database and a description as to how create teh national contributions. In addition a standard topographic base map was an essential prerequisite. So in many areas the IGME 5000 established basic standards where none exist.
Cooperation with International Participants and Scientific Advisors
Because the project involved the European and several adjacent countries, co-operation with the respective national geological surveys proofed to be essential. They needed to contribute draft maps of the pre-Quaternary geology of their land and sea areas and therefore required common technical guidance and provision with standards about the requirements of the procedure. Forty-eight geological surveys of Europe, Northafrica and Middle East were involved in the IGME 5000 (List of participating surveys and contacts). In addition the group of scientific advisors supported the project with scientific backing e.g. for the geology of the Mediterranean, the Alps, the Caledonides and the Baltic region, but also on paleogeological reconstructions, etc. The group mainly consisted of academics and members of international not-contributing geoscience institutions.
Setting Standards for the Analogue and Digital Data Preparation
Rather obviously the geological content is more than essential for a geological map. For that appropriate standards and workflows were developed to ensure that those institutions contributing to the IGME 5000 were working on the same geological, cartographical and geographical (topographical) basis and therefore supplied consistent input data.
Standards for the Printed Map
Preliminary Legend
For the geological draft map to be created by each participant for the area of their country, a preliminary legend (containing a preliminary classification of the geological units) as a part of Guidelines for the Preparation of Draft Maps was developed at BGR.
The preliminary legend defines the contents of the draft maps (and at the same time places necessary constraints of the contributing geologists). A number of partly hierarchically organised tables on age, petrography and metamorphism of the rock units are included in this legend (Asch, 1997a & b) which provided the basis for the more extensive term dictionaries for the database (see below).
Technical Guidance
More basic, but nonetheless critical, was the distribution of simple technical guidance notes for the preparation of the draft maps. Guidelines for the preparation of draft maps (Asch, 1997a) were developed which introduced a model of the draft map preparation, the required form of the finally submitted draft and the needed level of generalisation.
Common Topographic Base Map
Of fundamental importance is a common topographic base map. This controls the spatial referencing of the data but also needs to be suitable for printing (described in: Asch 1997b). The topographical base map was digitally available for free for all IGME 5000 participants and participants of co-operating projects, e.g. Geological Electronic Information eXchange System (GEIXS) or the 1 : 5 Million Map of the Soil Regions of Europe (European Soil Bureau). On the IGME 5000 Members Only Special Site the data were provided in the former common file formats (.gen and .e00) of the IGME GIS platform, ArcInfo (ESRI Inc.).
All IGME 5000 contributors were asked to use this topographic base map and to submit their contributions adapted to it, marking their geological units by individually created, unique identification numbers, the IN, which would be related to the general legend.
The submission of the draft maps was preferred in analogue form to avoid software incompatibilities and to avoid the need for digitising at the partner institutions.
Standards for the GIS
Term dictionaries
An essential part of any GIS is the database and the definition of its content and structure. This did not exist for the "region" of Europe at the required resolution. The term dictionaries were compiled on the basis of existing international standards as far as possible (e.g. for the classification of igneous rocks from Streckeisen, 1973, and Streckeisen, 1980; the chronostratigraphic classification of sedimentary rocks from the IUGS, 1998. However invaluable at this stage was the contribution of the academic advisors of the IGME 5000 (see Asch 1997b, p. 152).
Data Input Mask
Data input mask (template) for the database
To facilitate the data acquisition for the database and to involve the participating institutions in the generation of the database, a data input screen (or template) based on an MS Access runtime version was distributed to the IGME 5000 participants.
Based on the term dictionaries and a comparatively straightforward data model, the screen described in the Guide for Use of the Data Input Mask (Asch & Troppenhagen, 1998) provided information and limits on how the geological units may be described. While simple, the data model had to be developed with the opportunity for later modification towards a more sophisticated model in mind and moreover it must facilitate the necessary synthesis of the individual "country databases" considerably.
The descriptions provided were being collected in a database table, the "country databases" at the participating geological institutions. When the data acquisition was complete, the mask system also included functions to compress and copy the thus created individual database for mailing or e-mailing back to BGR (and to create a back-up for local use).
Data Harmonisation and Synthesis
Draft Maps
Harmonisation of the various draft maps of the countries
After the national draft maps were sent back to the BGR, the geological units and even the individual legends (because of the enormous variety of geological units) were being cartographically and geologically harmonised and generalised.
Database and GIS
Scheme for the unification of the IN
To create the database the following process was employed: on integrating the country-related data tables, the definive identification numbers (IN, see above) were harmonised by applying an algorithm so that finally only one combination of attributes relates to one identification number. This newly generated IN replaced the original IN national numerical coding of the geological units.
The editoral staff manually allocated the new IN to the units on the draft maps in the course of the geological harmonisation and the geological and cartographical generalisation.
After collation the linework of the European geological map was digitised and transferred to and further processed in ArcInfo. The primary key to the descriptions in the database were provided by the IN after they were added as attributes to the geological polygons. The entire procedure finally generated a database that comprises the attributes of all geological units and their IN as a link to a complete and harmonious European geological map with an unmistakable IN for all areas.
At a later state the thus created GIS enabled the production of a printed map, a web mapping application and extract maps to be produced on demand. In addition to the cartographic design, database retrieval functions, but also the visualisation tools for the CD ROM and internet versions were created. The potential requirements of the future users were central to the definitions of these products.
Copyright and Data Dissemination
An issue was that of data distribution and copyright. The question was, how to disseminate the digital data while retaining copyright. Thus, BGR retained the copyright in order to avoid indiscriminate commercial exploitation. All sources used for the map compilation are quoted and visible on the map face. This includes individual and organisational contributions, the advisory board and expert groups. All used publications (incl. maps) are quoted as scientific references.
The IGME 5000 is quoted as follows: Asch, K. (2005): IGME 5000: 1 : 5 Million International Geological Map of Europe and Adjacent Areas. BGR (Hannover).
References
AGSO (1993): Rights and Responsibilities of Spatial Data Custodians and Lead Agencies
Asch, K. (1997a): Guidelines for the Preparation of Draft Maps; Federal Institute for Geosciences and Natural Resources, Hannover
Asch, K. (1997b): The Development of a New Small Scale Geological Map of Europe as a GIS; Proceedings ScanGIS '97; pp. 149-155
Asch, K. & Troppenhagen, H.-G. (1998): Guide for Use of the Data Input Mask; Federal Institute for Geosciences and Natural Resources, Hannover
IUGS (1998): International Stratigraphic Chart, Strasbourg
Streckeisen, A.L. (1973): Classification and Nomenclature recommended by the IUGS Subcommission on the Systematics of Igneous Rocks. Geotimes, 10/73, pp. 26 - 31
Streckeisen, A.L. (1980): Classification and Nomenclature of Volcanic Rocks, Lamprophyres, Carbonites and Melilitic Rocks. IUGS Subcommission on the Systematics of Igneous Rocks. Band 69, Vol. 1; pp. 194 - 207.
Contact