Simulating past droughts and associated building damages in France

Abstract

Abstract. Droughts can induce important building damages due to shrinking and swelling of soils, leading to costs as large as for floods in some regions. Previous studies have focused on damage data analysis, geological or constructional aspects. Here, a study investigating the climatic aspects of soil subsidence damage is presented for the first time. We develop a simple model to examine if the meteorology has a considerable impact on the interannual variability of damages from soil subsidence in France. We find that the model is capable of reproducing yearly drought-induced building damages for the time period 1989-2002, thus suggesting a strong meteorological influence. Furthermore, our results reveal a doubling of damages in these years compared to , mainly as a consequence of increasing temperatures. This indicates a link to climate change. We also apply the model to the extreme summer of 2003, which caused a further increase in damage by a factor four, according to a preliminary damage estimate. The simulation result for that year shows strong damage underestimation, pointing to additional sources of vulnerability. Damage data suggest a higher sensitivity to soil subsidence of regions first affected by drought in the 2003 summer, possibly due to a lack of preparedness and adaptation. This is of strong concern in the context of climate change, as densely populated regions in Central Europe and North America are expected to become newly affected by drought in the future.

Drought-induced building damages from simulations at regional scale

“…In that case, however, the damages should not have been reported within the natural catastrophes insurance system. Finally, varying construction standard might play a role, yielding higher damages in regions affected by drought-induced soil subsidence for the first time in 2003 (Corti et al, 2009). …”

“…As in Corti et al (2009), we use an optimization routine inspired by nature, known as genetic algorithm (David, 1998), to derive empirical sets of parameters, such as vulnerability or soil shrinkage curves. For the soil moisture deficit indicator (Sect.…”

“…Certain soils shrink and swell in response to dry and wet conditions, inducing vertical soil movements, known as droughtinduced soil subsidence of expansive or shrinking soils (Corti et al, 2009). These soil movements can cause important damage to buildings and other infrastructure.…”

“…In a recent study, Corti et al (2009) presented a meteorologically-based model system (hereafter named C09 model) to simulate damages from drought-induced soil subsidence. The simulation results showed that the model is capable of reproducing observed annual drought-induced building damages in France.…”

Review article: Assessing the costs of natural hazards – state of the art and knowledge gaps

“…What all susceptibility functions have in common is that they describe the relation between one or more hazard parameters, with a resulting monetary damage for a certain type or use of object at risk (Smith, 1981;Parker et al, 1987;Wind et al, 1999;BUWAL, 1999;Keiler et al, 2006;Fuchs et al, 2007b;Corti et al, 2009;Totschnig et al, 2011;Holub et al, 2012). Hazard parameters include, for example, avalanche pressure, water depth or drought-induced soil subsidence.…”