Geomorphological indicators of paleodune fragility.

Abstract

The combined effect of the fragility of old coastal dunes due to its natural conditions and the human activities on dunes, produce their  estabilization and the beginning of geomorphological processes that lead them to a rapid transformation and landscape degradation. The occurrence and the mechanism of these morphodynamic processes are precised in this paper. In essence, they are geomorphological indicators of the fragility of paleodunes of the littoral of central Chile. These indicators of fragility are rills and gullies (due to vertical erosion due to the rain) and mass movement that affect the stability slopes of the old fixed dunes. The determination of the fragility of these naturals environments, done through the geomorphological indicators, is of great utility in the definition of environmental units of territorial diagnosis for land evaluation  urposes and for the physical planning of the coastal zone.