An integrated approach for debris flow hazard assessment - a case studyon the amalfi coast - campania, italy

Abstract

In this work, a multidisciplinary study is presented in which potential debris flow events are studied from their beginning to their end. The case study is located on the Amal Coast where historical events of debris flow are well documented in 1910, 1924 and 1954. An integrated approach was used for the geomorphology and geo-pedology of volcanic deposits. The matches found between morphotypes, depositional and pedological processes and soil characteristics made it possible to develop a detailed map of the soil deposits which was then used to estimate the geographical distribution of the parameters relevant in the stability analysis. The modeling of debris flow initiation process is carried out through a stability analysis of the soil after a rainfall characterized by a given intensity and duration. The debris flow volume corresponding to a given return period is subsequently obtained. The propagation of this volume is then simulated through a commercial, two dimensional model (FLO2D). Both modeling approaches, for the initiation and the propagation processes, are tested by comparing them with a historical event in 1954. The integrated procedure described makes it possible to draw up maps of debris flow intensity corresponding to assigned return periods. These elements may be easily elaborated in order to draw up debris flow hazard and risk maps.