Hydraulic stream network conditioning by a tectonically induced giant deep-seated landslide along the front of the Apennine chain (South Italy)

The tectonic stresses that produceding the uplift of Apennine chain ridge in Southern Italy generated advanced buried thrusts of allochthonous deposits that induced deformations of foredeep deposits. This thrust may cause giant deep-seated landslides at the front of the chain. Starting from a specific case history in low Biferno valley, this work presents how giant deep-seated landslides along the front of the chain may be generated by the thrust of allochthonous nappe of the chain. Besides, the influence that these huge phenomena may have on landslide and flood susceptibility and on natural hazard of the involved area are analyzed. The work presents an interpretations of local morphology and stream network paths of low Biferno valley as consequence of a giant deep-seated landslide affecting the right side of the valley. The proposed interpretation is, supported by numerical geomorphological analyses of the area at stake. It is shown how both the morphologies of the catchments of river Biferno and its tributary Cigno and stream paths are strongly conditioned by this large deep-seated landslide. This landslide deviates the stream paths affecting both the flooding susceptibility of low Biferno valley and landslide susceptibility on the left side of Biferno valley.