An area covered in water, which is normally not under water, is described as flooded. The underlying causes vary depending on where the flooding occurs; along the coasts, in rivers, in lakes or in cities.
Lakes and waterways
The risk of flooding in lakes and waterways might change in the future but varies between different parts of the country. Flooding due to extreme water flows may become more common in large parts of Götaland, southern Svealand and north-western Norrland, while the risk is estimated to be lower in northern Svealand, and the rest of Norrland. However the local differences are large.
The risk of flooding also depends on other factors such as how waterways are regulated, what preventive measures are adopted and how buildings and infrastructure will change.
Extreme precipitation that falls during a short period of time can cause major problems with flooding in cities. In urban areas runoff often occurs from small areas with high proportions of impervious surfaces, which cannot absorb any water. Storm water systems therefore have to handle a large part of the rainfall.
Research into extreme precipitation in a future climate suggests that this type of event is expected to become more common in the future. Adaptation efforts can be made to build resilience to extreme precipitation in urban areas.
Both sea-level rise and land rise affect the risk of flooding along the coast. Sea levels are expected to rise over a very long period in the future. The land rise means that the local sea level rise will be lower in the central and northern parts of Sweden, and higher in southern Sweden.