GEOLOGICAL MAPPING IN URBAN AREAS. A CASE STUDY FROM THE INNER CITY OF THESSALONIKI, GREECE

The methodology of geological mapping in urban areas differs from the ordinary field research. An urban area has no outcrops, has a smooth surface, diverted water lines and covered geology. The data types commonly collected in urban areas are from few outcrops (if there are some), borehole records, geophysical prospecting data, geological maps, digital elevation models (DEM), shallow excavations, palaeoseismological trenches and publication archives. This research at subsurface of the city produces new thematic maps for the initial surface under the building area, the water network, the geology and finally the fault system. This paper demonstrates a methodology and provides a way to solve engineering geology problems in urban areas