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FLOODMAGE: from damage compensation to risk prevention

Italy is a highly subject to hydrogeological risk, and climate change will likely increase the danger of meteorological events. However, much of the money that should be spent on risk mitigation and adaptation ends up spent for compensating the inflicted damage to privates and business activities. Almost every year, floods of different origin hit the Italian territory. River overflowing, urban surface floods and coastal storm surges are events that develop with different dynamics, but the landscape they leave behind them afterward is the same: clusters of rubble made of damaged appliances, fragments of walls and fences, car-casses, desperate people and a lot of mud.

Flood of 2015 in Genova

Floods are intrinsically linked to the dynamics of natural processes and their variability. When these events occur near or within anthropized areas (homes, businesses or infrastructures), they cause a damage which can be classified in terms of:

  1. Direct monetary costs (damage to property)
  2. Indirect economic losses (interruption of the production)
  3. Injuries and loss of lives (not monetizable)

Flood losses in Italy (1990-2015) in terms of human fatalities and GDP share.

In its history, Italy has undergone numerous disastrous events that inflicted heavy losses on the territory and the populations that inhabit it; for example, the devastating Polesine flood (1951) which radically influenced the economic development of the area, or the flood that affected the entire Arno basin, devastating Florence (1966). Considering the last two decades, more than thirty events have caused casualties.

Flood of 2014 in Modena (Secchia River).

Legambiente estimated that in Italy about one in ten people live in an area subject to hydrogeological risk; a third of those reside in a high-risk area, that is, where events repeat with a return time between 20 and 50 years; translated in economic terms, Italy pays more than any other European country to compensate for the costs inflicted to companies and individuals not insured against flood risk (65 million Euros) and, after France, records the highest number of victims in Europe among the 1980 and 2015 (EEA, 2017). This is only partly due to the change in climatic conditions; the danger of extreme events is in fact amplified by the uncontrolled expansion of urbanized and cemented areas and by poor risk prevention.

When a river overflows in sparsely populated agricultural areas, the damage is limited, sometimes even absent. But if the same agricultural areas exposed to risk have been transformed into productive sheds and apartments, then the value exposed to risk increases and so does the potential damage. In addition to this, the uncontentested process of urbanisation and soil sealing prevents rain from infiltrating the soil, causing large volumes of water to accumulate rapidly in the riverbeds and in the flow channels, summing up into sudden flood waves that can overflow the embankments, or destroy them.

Floods are difficult to predict; if it is true that some events show recursive behaviour (which means they repeat with similar characteristics in the same area), the fact that an area has never been affected by a flood event does not mean that it will not be affected in the future. In order to identify potential changes in the frequency of disastrous events and plan adequate risk mitigation measures, modeling uses a range of different approaches depending on the type of impact to be identified.

The FLOODMAGE service was designed to integrate these different approaches into an integrated framework which, starting from the estimates of alluvial probabilities elaborated in connection with the projections provided by the climate scenarios, measures the direct impacts (economic compensation costs) and those indirect (loss of production) at the micro-scale level. The direct damages are estimated on the basis of the total value attributed to the buildings (reconstruction and replacement costs), while the indirect ones are elaborated by a regional macro-economic model starting from the economic shock (interruption of the service) suffered by the companies for the three macro sectors, i.e. agriculture, industry and services.