New general engineering geological map of Slovenia
The new lithostratigraphic map of the entire Slovenia (in the scale of 1:250000) created by using the GIS method enabled the production of its derivative - engineering geological map (EG map). The goal of creating this map was to define the general engineering geological characteristics of rocks and soils that will be used for the general review of engineering geological conditions in Slovenia. The map also enables the planing of general interventions in Slovenia. The EG map was created by using the GIS method for merging the lithology units of Slovenia according to EG characteristics on three levels. The first one is the basic separation into soils, soft rocks and rocks. The second level is a more detailed separation on the basis of their origin and the third one on the basis of the composition, rock strength and particle size ranges. The first basic GIS layer determined the EG units merged with the database, giving the spatial and description data for each unit. The basic data for each unit was stored in the GlS-database (serial number, the connection to the lithology unit, the name, short description, comprehensive description, the occurrence in Slovenia). The EG units were also stored in the database (the description of EG units, geotechnical characteristics, the foundation conditions, seismic characteristics). The map was further detailed by the creation of informational layers derived from the map. In this manner the map of rock strength, the map of possible land sliding, the map of weathering cover thickness estimation and the erosion map were produced. The GIS modelling method was used for the creation of these maps. For example, the map of possible land sliding was created regarding these informational layers: lithology structure, the thickness of weathering cover, the slope inclination and the hydrogeological conditions.