Scenari di allagamento dovuti a possibili cedimenti arginali: il caso del Canale Roncajette

In this thesis we analyze the flood effects produced as a result of flooding overtopping or levee breaching in river contexts. The problem is of considerable economic, social and environmental interest, especially in prospect of planning to reduce hydraulic hazard: the submersion waves that arise due to insufficiency or collapse of levee structures can in fact cause the lost of human lives, huges damages to the affected properties and ecosystems. The study is conducted on the basis of a one-dimensional hydrodynamic model of finite elements that solves the equations of long waves in low waters, modified appropriately in order to treat the dry-wet transition processes on irregular soils. The fixed-bottom model allows to simulate the collapse of a levee structure through the formation and evolution of a breach caused by siphoning or overtopping. The surveys are conducted in the context of a joint analysis of mathematical modeling and geophysical analysis of data acquired on the Roncajette Canal (PD), both previous and in the context of this thesis. The presence of levee segments with physical properties that reveals aspects of a possible weakness of the levee section suggests that in a flood event similar to the one November 2010, the Roncajette Canal could be inclined to reach conditions causing the formation of levee breaching. The conducted surveys made it possible to produce a series of thematic maps in which the location and extension of flood risk areas were highlighted due to the phenomenon investigated.