Flood risk is commonly understood as the product of the probability and consequences of flooding. There are various mechanism through which floods occur: local precipitation (pluvial); rivers or seasonal snow melt (fluvial); sea (tidal, storm surge); or precipitation in steep catchments and fast runoff (flash floods). As floods are influenced by the complex and dynamic interaction between physical and human systems, flood events are highly unpredictable.
Of all the natural hazards in Europe, flooding is the most common, and accounts for the largest number of casualties and highest economic damage (Guha-Sapir et al. 2013). Unlike other natural hazards, no European country is free from the risk of flooding. Between 2000 and 2005, Europe suffered nine major flood disasters, resulting in 155 casualties and economic losses of more than € 35 billion (Barredo 2007). The 2013 floods in central Europe caused 25 casualties and $15 billion economic damage (Munich Re, 2014). The winter floods in 2013 and 2014 in different parts of the UK flooded 5000 homes and caused 17 casualties and over £2 billion worth of damage. In October 2015 the French Riviera was severely flooded causing at least 19 casualties and ca € 625 million damage . These recent events highlight the challenge and importance of effective flood risk management.
Without additional actions, both the probability and potential consequences of floods in Europe are expected to increase. Climate change is expected to result in sea-level rise and to induce more extreme weather events, increasing the probability of flooding (IPCC 2011). On average, in Europe, flood peaks with return periods above 100 years are projected to double in frequency within three decades (Alfieri et al 2015). Soil subsidence may aggravate flood risks, mainly in delta regions. At the same time, the potential consequences of extreme weather events are enlarged by population growth, economic growth and urbanisation in flood prone areas (Barredo 2009; Mitchell 2003).
STAR-FLOOD stands for: “STrengthening And Redesigning European FLOOD risk practices: Towards appropriate and resilient flood risk governance arrangements”. The project was focused on analysing, explaining, evaluating and designing policies to better deal with flood risks from rivers in urban agglomerations across Europe. Case studies have been performed in 18 vulnerable urban regions in six European countries: Belgium, England, France, The Netherlands, Poland and Sweden. The results of this ambitious project are highly relevant for developing and implementing new policies and law at the European, national and regional level and for the development of public-private partnerships. STAR-FLOOD lasted from 1 October 2012 until 31 March 2016.