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The main principles accuracy, simplicity, clearness, self explanatoriness always lead to genera 
lisation using symbols. So maps can be considered as a sophisticated data reduction method. As 
it is necessary to hold the balance between complexity of graphical configurations and ease of 
interpretation, some background information is required to read a map properly. 
To obtain the background information, it is necessary to meet the responsible person(s), which 
is often very time consuming. There is also quite a high turn over of the scientific staff and as 
consequence spatial data loose very quickly their value for further scientific work if the 
responsible person is no longer involved in the studies and if the spatial data are not very well 
documented. So a meta database for spatial data was considered a necessary tool within the 
FAM project. The meta information about the experimental field results and laboratory analysis 
are stored in the FAM database together with the raw data itself. 
4.0 METADATA STANDARD 
Facing the need of standardisation of spatial meta information in 1994 the Federal Geographic 
Data Committee (FGDC) presented a standard and approved the „Content Standards for Digital 
Geospatial Metadata". The standard specifies the information content of metadata (data about 
data) and provides a set of terminology and definitions for the documentation of spatial data. 
The Executive Order 12906 coordinates the geographic data aquisition and access and should 
help federal agencies to use the standard and document geospatial data beginning in 1995. The 
FGDC established through the Office of Management and Budget is charged with the respon 
sibility to coordinate various surveying, mapping and spatial data activities of the federal agen 
cies to avoid duplications and minimize costs. 2 
The FGDC defines seven elements: Identification information. Data quality information, Spa 
tial data organisation information, Spatial reference information. Entity and attribute informa 
tion, Metadata reference information. The standard has sections to specify contact person and 
organisation and citation information. 
4.1 METADATA STANDARD IN ARC/INFO 
The GIS Arc/Info (Version 7.03) ESRI Inc. has parts of the standard implemented on the basis 
of the relational database management systems. The tool 'document.amf consists of four INFO 
tables and permits the input and retrieval of spatial information. Coverages and grids can be 
documented and several information about the geometry (number of arcs, nodes, segments, 
projection etc) are generated automatically in the background. The following tables are produ 
ced: 
cover.doc layer specific information 
cover.ref data sources information 
cover.aat attribute information 
cover.nat additional information 
4.2 MERAKA (META INFORMATION SYSTEM OF GEOSPATIAL DATA AND MAPS) 
As in the FAM project the metadata for the experimental non geometric results (e.g. the 
sampling method, chemical analysis, statistical calculations, name of theresponsible scientist) 
are stored in the Ingres FAM database, there is a link in MERAKA to the corresponding table. 
2 URL:http://fgdc.er.usgs.gov/metaover.html