The Earth surface and its discrete evaluation

Abstract

Contrary to views of A. N. Lastochkin, discussed in the paper, the author is of opinion that the topography representation on maps by means of isolines is not necessarily continuous, gradual and unambiguous. Landforms and their elements should be identified using structural lines based on extreme values of elevations, their 1st and 2nd derivatives that, in turn, require the elevations to be rigorously set as a function of horizontal coordinates, which is not possible as yet. Hierarchic classification of the surface landforms is needless if only morphology matters, though it becomes necessary when the genesis and age of the relief are considered.