An approach to organize loss data related to geo-hydrological hazards

Paola Salvati, Ivan Marchesini, Carmela Vennari, Marco Donnini, Cinzia Bianchi, Alessandro Sarretta, and Domenico Casarano, 2020, An approach to organize loss data related to geo-hydrological hazards, EGU General Assembly 2020, online, 4-8 May 2020,

Most commonly, geo-hydrological hazards (i.e., landslide, flood, sinkhole) occur in response to a single trigger like an intense rainfall event, a prolonged rainfall period, a rapid snowmelt event, an earthquake. Multiple damaging processes (phenomena) occurring in response to a single trigger can cause a cumulative socio-economic impact, which is often difficult to quantify and to attribute to each single damaging processes (landslide, or a group of landslides, or a single inundation). As a consequence, after a geo-hydrological disaster occurs, media, insurance companies and international institutions publish numerous assessments of the cost of the disaster based on different methodologies and approaches, often reaching different results. At European level, EC Directives related to natural hazards prove standards for the collection of data focusing their attention mainly on codifying the processes, their attributes and their spatial extent, leaving out the important issue of rigorously classifying the damaged elements and the loss data. Lack of standards contributes negatively to the paucity of damage information and cost data, fundamental for the successive ex-post analysis aimed at quantitatively risk evaluation. In Italy, despite the frequency of the significant socio-economic impacts due to geo-hydrological hazards, few attempts have been made to estimate the economic cost of geo-hydrological hazards. These loss estimations are mainly based on cost components of the public budget for post-event restorations and reimbursements, hampering the possibility to distinguish between the private and public sector losses. The loss estimates do not distinguish the costs (i) by type of processes (landslides, flash floods, floods and other damaging events) responsible for the damage, and (ii) by expenditure items (restoration actions or mitigation activities). LAND-deFeND, a recently developed database structure, represents an effort to manage all the issues that can arise when storing, organizing and analysing information on losses related to geo-hydrological hazards with different levels of accuracy and at different geographical scales, from the national to the local scale.

Data from