Economic evaluation of flood damages and identification of priorities defining mitigation measures actions

Flood risk is one of the most important topics under study of international researches usually associated at climate changes and unrestrained urbanisation resulting in a strong instability of weather conditions requiring a better control and forecast of climate trends and land use. A glance on current disasters around the world shows the relevance of flood risk and a continuous adjournment guarantees the awareness of the population about the dangerousness of flood effects. The analysis of potential floods shows several and different types of flood that could be grouped mainly in flash flood, fluvial flooding, coastal flooding and urban flooding. The most part of damages caused by these floods are linked with gaps on urban regulations that allow the realisation of built-up areas on unstable land as reclaimed lagoon, banks river area that create river path diversions, on coastal area as dunes or close to beaches, or even along river paths used to discharge volume of dams when the water level is close to the acceptable maximum level. Even though the improvement on technology, the impossibility to predict accurately weather conditions and the consequent uncertainty are worsening the situation of areas usually under flood risk. The deepened analysis conducted on flood event underlines the necessity to enhance the management of the flood risk forecasting the disasters and modelling potential scenarios with adequate hydrologic and hydraulic models in order to ensure right depicting of flood process development. The modelling of results as flow rate, water depth and flow velocity is fundamental to get hazard and risk flood maps that act as a springboard on a success predisposition of flood risk management plans. In the flood risk management plans, the identification of flood hazard and flood risk maps are used to define mitigation measures, usually divided in two main groups: structural and no-structural measures. The choice on the activation of structural and no-structural mitigation measures is mainly based on financial availability, time-step in measure realization, stakeholders preferences and government authority decisions. The considerable costs in realisation of mitigation measure is usually shore up by costs-benefits analysis methodologies representing a relevant support for decision makers. This research is focused on the definition and implementation of methodologies to evaluate potential flood damage of a baseline scenario and to support definition of mitigation measure scenarios. The work aims to identify the magnitude of the flood in terms of potential damages assessed considering the two main categorises of tangible and intangible damages. The flood damage evaluation is, herein, conducted with methodologies for an economic appreciation of the damage and implementation of models able to evaluate the potential number of fatalities and injuries due to flood meant as intangible damages reducible with efficient warning and evacuation issuances of flood emergency plans. These methodologies include different fields of research as hydrologic, hydraulic, agrarian, social, geological and political subjected at relevant uncertainties data included on the study.Finally, the damage reduction could be obtained implementing no-structural mitigation measures as the predisposition of flood management plans that include rules and tasks proper of flood emergency plans. Recent floods reveal that a correct preparedness of population and authorities on flood emergency reduce significantly damages and in particular victims and wounded. In fact, the second aim of in the project study the civil protection actions identified as crucial in the emergency management to prevent damages so much to require the identification of proper warning and evacuation time issuance, how they should be disseminated by the civil protection and local authorities after an accurate monitoring of climate conditions and management of people moves towards safe haven.