The digital model of an object or phenomenon is constituted of a data collection systematically stocked (data base) that describe a tri-dimensional system of coordinates, arbitrary or particularly can form the object features or states/accomplishments of the phenomenon (conversion as a digital image) and allow by calculation programs, deducting the object or states shape and features for the phenomenon in new points. Modelling the areas is the process for representing graphically a natural or artificial area by using one or more mathematical equations.  Modelling the terrestrial area is a particular case for modelling an area where we should take into account the specific problems for representing the Earth or some of its parts. From the fields where the digital model can have an immediate applicability are as follows: analyse of telecommunication systems, designing the pipe networks (water pipes), command and control of different systems, as in all other fields where it is necessary to know the altitude information in different points of an area. The term of „digital terrain model” was used for the first time in 1958 by Miller and Laflamme who defined it as “a statistic representation of continuous area by using a great number of points whose horizontal coordinates (x, y) together with the altitude (z) are known and this representation is made in an arbitrary coordinates system”. The digital terrain model represents an informatics’ instrument composed by terrain data and software that represent a basic component of a GIS. The digital terrain model (DTM) is composed by 3 sub-systems: Digital elevation model- DEM contains altitudes, slopes, curves, etc. Digital planimetric model – DPM contains planimetric data and elements. Digital model of objects nature – DEN contains pedologic, geologic, hydrologic data etc. Generating the DTM refers to the way of data acquisition, to making the model by using different interposing methods and also choosing the structure of data representation (raster or TIN).

sustainable development; Environmental protection; G.I.S.; modeling; digital terrain model

Presentation: oral