On the role of soil properties and initial conditions in the response of river levees to flood events

In the context of changing climate and growing population, river floods pose an escalating threat for the human and economic losses that they may cause. The current earthen defence systems are crucial assets for the safety of the built environment but require a reliability as-sessment and possible renovation to keep up with new safety standards. To this purpose, the numerical methods represent an effective tool, when the soil-atmosphere interaction is accu-rately modelled and the relevant constitutive parameters are identified. Their effectiveness hinges also on the possibility to use environmental data from site monitoring as input loads. Within this framework, the paper presents thermo-hydraulic finite element analyses of a floodplain and river levee, aimed to assess the system response to a flood event. The role of two aspects is discussed: (i) the unsaturated soil properties, namely the soil water retention curve and the permeability function, and (ii) the soil initial saturation condition that depends on the environmental load history preceding the flood event. The results confirm that the soil’s natural capability to mitigate the flood event is driven by its saturation condition.