Terrain modelling generates a digital picture of morphological and geological conditions using a large amount of three-dimensional point data.It is used for the presentation of terrain surfaces, trenching, filling and geological layers in order to achieve a vivid visualisation and as exact as possible a volume determination for planning construction trenches, stockpiles and landfills.In this way, for example, the volumes of soil qualities which can be structurally separated can be determined in a more precise way, ensuring economically optimal disposal.