Introduction

Climate change induced Geohazards (e.g. landslides, earthquakes, flooding) are increasing, endangering many historical buildings and putting at risk existing and future infrastructure investments in Europe. At present damage from climate extremes to critical infrastructure in the transport, energy, industrial and social sector totals €3.4 billion/year in Europe, which could triple by the 2020s and will continue to grow multiplying six-fold by mid-century and amount to more than 10 times by the end of the century (UK Climate Change Risk Assessment 2017). Moreover, expected annual exposure to multiple hazards will increase much more sharply than for single hazards (UK Climate Change Risk Assessment 2017). A systems approach is needed in order to promote better informed decision-making. This requires a strategic approach integrating land-use planning, national infrastructure priorities, building design, sustainable natural resource management and effective emergency planning.

A trend of increasingly frequent intense rainfalls and changing rainfall patterns in the long-term is increasingly causing flooding events. In the last decade especially, a trend of increasingly catastrophic flooding events has taken place in Europe, where an area as big as 40,000 km² , housing 16 million people, is flood prone (Floodsite, 2007). More recently, in 2016 there was series of storms in Europe, mostly in Germany and France, which resulted in >26 people losing their lives, thousands trapped in homes or cars and more than 20,000 homes without power; this was due to rivers bursting their banks and the flooding of transport infrastructure. In Germany alone, direct economic loss amounted to €1,259 million caused by the damage to public infrastructure and buildings, private homes, businesses and farmland. To improve the current situation, a step change in the way we design resilient flood defence structures is required.

Transport networks across Europe also suffer severe delays due to failure of man-made ground embankments – the reasons for failure are still poorly understood and often occur unexpectedly in areas deemed secure, causing havoc to the entire network with consequent knock on effects. An example of this is the disruption caused by the flash floods in June 2016 to the UK rail network (NetworkRail, 2016). Improved geotechnical analyses of these earthworks, which have typically been constructed using locally available soils could reveal the causes of these failures and lead to substantial maintenance savings; for instance the UK alone currently spends £450 million per year on the maintenance and construction of new flood defence embankments (Dyer et al., 2009).

With regard to landslides, Europe has experienced the second highest number of fatalities and the highest economic losses caused by landslides compared to other continents: 16,000 people have lost their lives because of landslides during the last century (Safeland, 2012). In the period 1995-2014, 476 major landslides claimed a total of 1370 lives and damaged or destroyed an extensive amount of infrastructure, including roads and houses (Haque and Blum, 2016). Since 2008 there has been an increasing trend of fatal landslides, mudslides and debris flows triggered by an increase in natural extreme events such as storms (i.e. heavy rainfall) and floods. Among the largest events in terms of fatalities and destruction were the debris flows in Sarno in 1998 (Italy), claiming 160 lives, and the mudslides in Messina in 2009 (Italy), killing 31 people (EEA, 2009). These major events represent only a glimpse of the real impact of landslides, with a total of 712,089 recognised mass movements recorded in Europe since World War II (Eurogeosurveys, 2010). The economic scale of this problem as shown by the expenditure to protect against landslides in European member states (e.g. Italy spent approximately 3.9 billion Euro per year). Damage caused by landslides and floods also triggers annual economics loss in other countries such as in Germany (0.3 billion Euro/year (Haque and Blum, 2016)) and Spain (0.17 € Billion/year (Shuster, 1996)).

To make matters worse, more extreme climatic variations will likely not only increase the incidence of geohazards (e.g. floods, landslides) by inducing even more extreme weather conditions, but also accelerate the current rate of soil erosion especially along vulnerable coastlines and cliffs, which also put infrastructures and assets in danger (UK CCRA 2017). The Intergovernmental Panel on Climate Change long report published in 2012 and 2014 (IPCC 2012, 2014) predicts with high confidence that future changes in heat waves, glacial retreat, and/or permafrost degradation will increase the occurrence of landslides. Also an increasing number large rock slides during the past two decades has taken place in the European Alps, especially during the first years of the 21st century (Ravanel and Deline, 2011).

Furthermore, several European countries are prone to a high level of seismic activity. During the recent 2016 earthquake in L’Aquila (Italy), 297 people were killed, and more than 15,000 left homeless. Other powerful earthquakes causing several casualties occurred in 1999 in Athens (Greece), in 1981 in Irpinia (Italy) with 2,914 people killed and 300,000 left homeless. Therefore research is needed to improve our risk assessment of areas subject to earthquake induced mass movements (landslides, rockfalls, avalanches) and consequently at risk of fast debris and mudflows stemming from the mass movement taking place (landslides) and from earthquake induced soil liquefaction.

The Aim of this project is to provide a step change in terms of our predictive capabilities and assessment of climate induced geohazards risks and use this understanding to help engineer and fund 21^st century resilient infrastructure. This will result in reduced damage to buildings and infrastructure and the associated disruption to economic activities, and most importantly in reduced loss of human life. Also the research will produce a step change in the way insurers operate in calculating risk: current calculation models assume that risks are incalculable and therefore subject to randomness. However climate change induced geohazards have a precise a physical cause. The current inability to include physico-mechanical principles in the calculation of risks has led the insurance industry to rely on black-box models for the risk assessment which are uneconomical and do not properly reflect how risky a natural hazard is in comparison with other risks. Better understanding of the physico-mechanical causes of climate induced geohazards is pivotal to allow the establishment of cause-effect links between hazards and potential losses. This will lead to fairer insurance premiums and in turn reduce the use of exclusion clauses, sublimits, and coverage ceilings by insurers.