Flooding

In Europe, the natural hazards that cause the highest economic losses are flooding and storms. In warmer climates that intensify the water cycle, projections show a further increase in the risk of river floods in many western European and central eastern European areas. Urban drainage flooding is also expected, particularly in western and northern Europe, and so are coastal floods. Flood risks in a city can be strongly impacted by factors outside the city boundaries, such as upstream river management
Multiple factors influence the exposure to floods, the sensitivity to them and the response capacity (table). The following maps depict some of these factors, and provide some indication of the situation (in green). They need to be interpreted as a whole, together with the other factors still requiring local or qualitative information.

Factors that tend to increase the vulnerability to flooding by rivers, sea or heavy rain fall…	Response
Exposure	Sensitivity
High share of low-lying urban areas, potentially prone to flooding	High share of low-income households - socio-economic status	Decreasing soil sealing
High and increasing degree of soil sealing	High share of vulnerable people	Increasing the share of green urban areas
Lack of green urban areas	High share assets (commercial, residential areas) in potentially flood prone areas	Commitment to fight climate change - awarenes of and trust in the city governance
Increase of frequency and intensity of heavy precipitation	Key services like transport and energy infrastructure in potentially flood prone areas	Trust in other people
Increase of frequency and level of river floods	High population number in potentially flood prone are	Education
Sea level rise in combination with storm surges	High share of very young population	Socio-economic status - financial resources
Geographical location (at coasts or rivers) and topography (low-lying)	High share of lonely pensioners households	Awareness of business and citizens
Snowmelt	...	Well-functioning institutional structures and processes
High soil moisture levels		Sufficient capacities in administration to act
...		Availability of flood defences and retention areas
		Effective sewage system
		…