  Geometrical properties of landscapes result from the geological processes
that have acted through time. The quantitative analysis of natural relief
represents an objective form of aiding in the visual interpretation of
landscapes, as studies on coastlines, river networks, and global topography,
have shown. Still, an open question is whether a clear relationship between the
quantitative properties of landscapes and the dominant geomorphologic processes
that originate them can be established. In this contribution, we show that the
geometry of topographic isolines is an appropriate observable to help
disentangle such a relationship. A fractal analysis of terrestrial isolines
yields a clear identification of trenches and abyssal plains, differentiates
oceanic ridges from continental slopes and platforms, localizes coastlines and
river systems, and isolates areas at high elevation (or latitude) subjected to
the erosive action of ice. The study of the geometrical properties of the lunar
landscape supports the existence of a correspondence between principal
geomorphic processes and landforms. Our analysis can be easily applied to other
planetary bodies.
