Preparation and Evaluation of Engineering Geological Maps in 3-dimensional Geographic Information Systems Environment

Geological engineers have mostly been involved in geotechnical problems since the beginning of 19 century. Engineering geological maps and field data are needed to solve these problems. The amount of data for these maps is extremely large, so putting all the map elements on the map sheet causes difficulties while solving problems. The magic words, Geographic Information System (GIS) is a tool for modelling real world by use of computer technology. Mostly 2-dimensional GIS is used in many different application fields. Even this 2-dimensional GIS is used for many geoscientific studies, 3-dimensional modelling must be used if variation of subsurface is needed. 3-dimensional GIS is used for the preparation of engineering geological maps and evaluation of geotechnical problems for one of the municipality of Istanbul metropolitan area. It is seen that, for project like preparation of engineering geological map which use data such as multiple points from one boreholes and threedimensional geotechnical data 3-dimensional GIS is needed. 2-dimensional GIS must be used with some graphics and bar charts which presents depth data with the real 3-dimensional GIS especially for geoscientists.