RIORGANIZZAZIONE DEL RETICOLATO IDROGRAFICO NELLA COLLINA DI TORINO IN RELAZIONE ALLA DEFORMAZIONE QUATERNARIA (NW ITALY)

Abstract

Forno M. G. & Boano P., Re-organization of hydrographic network in the Torino Hill connected to quaternary
deformation. (IT ISSN 0394-3356, 2007).
The hydrographic network, remarkably conditioned by the gradient of the topographic surface, is a very reliable marker of the morphological modifications of an area. It can consequently become a significant and sensible marker of the recent deformation.
Numerous examples of re-organization of hydrographic network are pointed out in the Southern slope of the Torino Hill: they are induced or favoured by the quaternary evolution of the anticline.
In the considered examples the possibility of the adaptation of hydrographic network is conditioned by the watercourses incision
degree, connected with the incidence of the deformation.
Near the syncline axis of the Poirino Plateau a very weak gradient variation occurred, connected to the recent deformation: in this area
the scarcely entrenched hydrographic network is sensible to the gradient variation, and the previous valleys may be left. An inversion
of the drainage can therefore occur: the main watercourse, before flowing to the East, now flows to the West.
In the sides of the anticline structure of the Torino Hill a remarkable increase of the inclination took place, connected to the recent
deformation: in this area the hydrographic network preserves the evidence of ancient trends, cut progressively by the present network.
Near the anticline axis a very strong increase of the gradient finally occurred, connected to the recent deformation: in this area the
watercourses, entrenched in the previous trends, are not subject to direction variations; on the contrary they are subject to deepening of the lower stretch because of the new gradient.