The determination of landforms of the terrain depends on a number of procedures. In general, all these procedures can be subdivided into two groups. The first group consists of measurement activities related to obtaining real-life data. The second group comprises operations related to the processing of results, in order to obtain the imaging. The measurements of the terrain and its landforms are discrete. Cartographic images are continuous. In order to get a map of 3D measurements, contours need to be interpolated. In this publication, four of the many interpolation methods were selected for presentation: Global Polynomial, Inverse Distance, Radial Basis Function, and Kriging. The example of the measurement results for a syncline (a subsidence trough) is used in order to illustrate the comparison between the modes of operation of particular methods.