Increased flooding is likely to be one of the most serious effects from climate change in Europe over coming decades. Some of the conditions which may contribute to urban flooding are highlighted in an Eye on Earth map from the European Environment Agency (EEA).
The map is one example of the capabilities of Eye on Earth, an online mapping tool created by the EEA and partners. From 4 to 6 March 2013 the EEA is organising the First Eye on Earth User Conference in Dublin, Ireland. The event will bring together people with a common interest in sharing environmental data and information for public access.
What does the map show?
During heavy rain, cities may be flooded if the water cannot drain quickly into the ground and the sewage system in cities cannot cope with the amount of water. For this reason, the map also shows the mean percentage of each city covered with impervious surfaces such as buildings, concrete or asphalt, where the soil is ‘sealed’. Paris, Thessaloniki, Bucharest and Barcelona are just some of the cities with more than three quarters of their surface area sealed, meaning that there may be a risk that water cannot disperse so quickly into the ground during heavy rainfall.
However, it is important to be aware that soil sealing is only one factor contributing to increased risk of urban flooding. In 2011, extremely heavy rainfall in Copenhagen caused widespread flooding and damage when the sewers could not cope with the huge volume of water. Insurance damages alone were estimated at € 650–700 million. However, around 60% of the area of Copenhagen is sealed, less than many other cities.
A high amount of artificial areas also increases the temperature in cities. Interestingly, a 2012 EEA report on urban adaptation to climate change noted that green spaces can also help during heat waves by cooling urban areas. In some areas of Europe the number and length of heat waves is also expected to increase due to climate change, visually depicted in this map.
Climate change has been observed across Europe, according to another EEA report published in 2012. The effects are very varied across the continent. For example, precipitation has increased in the north, but decreased in the south, and most projections show that both trends will continue throughout this century.
Source : European Environment Agency (EEA)