GIS utilization in determining the limits between low morphological units.

The limit between low morphological units is quite difficult to be established due to the fact that the lithological, elevation and/or structure differences are hardly visible. Thus, the contact between piedmont and plain units is represented, in many cases, by areas where limits are hard to be drawn. In order to establish the way geographic information system (GIS) may contribute to the determination of the aforementioned limits, we used the situation of the limit between the Getic Piedmont and the Romanian plain and compared the obtained results to examples from other areas with different formation and evolution conditions. Presently, the Getic Piedmont undergoes a modelling process as valleys widen, torrential enlargements laterally advance, and slope denudation develop, which make difficult to establish a clear southern limit. The fan texture of the valleys, their age, the flowing direction, as well as the differences of altitude, lithology, and structure disposal represent the main elements when establishing limits even in the case of GIS analysis. The drawing of thematic layers rendering elements such as hydrographic system, hypsometry, DEM on a traditional cartographic support, orthophotoplans, satellite images, for a better interpretation of the geomorphologic aspects allow a more objective attempt of reconstructing the morphological limits.