Web mapping is the perfect delivery mechanism for geological information - and thus for the International Geological Map of Europe and Adjacent Areas (IGME 5000). It allows international access to a map and underlying data, it could, if desired in the future, remove the significant cost of printing and distributing paper maps and CD ROMs and, lastly, it is dynamic and flexible and can allow users to access more than just the restricted features which appear on the printed map face.
The IGME 5000 is a major European geological GIS project being managed and implemented by the German Federal Institute for Geosciences and Natural Resources (BGR) under the umbrella of the Commission for the Geological Map of the World (CGMW). It is a collaborative European project that involves 48 Geological Surveys and is supported by a network of scientific advisors. The original aims of the project have now been achieved: to develop a Geographic Information System (GIS) containing up-to-date harmonised lithological and geochronological data of Europe, and to print a geological map of the pre-Quaternary on-shore and, for the first time at this scale, off-shore areas of Europe.
The IGME 5000 map is based on a spatial database which connects the attributes of the geological units with the visible graphical objects (points, lines, areas) on the map, i.e. on screen. The spatial database is connected to the GIS by an ODBC interface.
The concept of the geological map of Europe as a GIS allowed the development of a web mapping application. Here an initial key map allows the user to define the area of interest and select the chosen geological theme (e.g. Jurassic sedimentary rocks of onshore Europe, or ophiolite complexes of the Dinarides) through a Windows-operated menu. Users are now able to tailor a map according to their own requirements, selecting areas on the map and geological units according to e.g. the age and/or lithology of the rocks. Each unit when clicked on shows a pop-up window listing its attributes in the databases which embrace lithology, age, genetic and tectonic elements, regional names and metamorphic features. A main graphic window displays map/spatial data; a dynamic legend adopted to the displayed map data is provided; a range of buttons provides practical functionality, such as zoom, pan, select, query and print. The application was being developed based on the UMN mapserver and the tools PHP and mapscript which has the advantage that of no additional software needs to be installed for viewing the data. This Web GIS application represents the central feature of the IGME 5000 internet site. It can be can be accessed through the following URL: http://www.bgr.de/app/igme5000/igme_frames.php.
When the IGME 5000 project was initiated in 1994, a web-enabled GIS was no more than a concept. Today the concept has become a reality and may become key information resource to aid to understand of the complex and unique geological history of the continent.