Höjning av vattennivån i Mälaren : Ett hot mot Stockholms centrala delar vid en framtida klimatförändring?

In today’s World is climate change an important and hot topic. Climate scenarios for Sweden show a warmer climate, especially during the autumn, winter and spring. The same climate scenarios also show that the precipitation will increase during this part of the year, however, during the summer the opposite is expected to occur. The purpose of this essay is to examine how future climate change will affect Stockholm especially the expected increase in precipitation, which may lead to a rising level of the Lake Mälaren. During 2000/2001 was Stockholm hit by a flood. This flood nearly resulted in major consequences and showed that there were significant risks for the city of Stockholm and increasing precipitation will result in even more water in the drainage systems of Lake Mälaren. The results presented here show that it is important to increase the drainage capacity of Lake Mälaren in order to reduce the risks of flooding in the central parts of Stockholm. The consequences of a rising level in Lake Mälaren, corresponding to a hundred years flow will result in a risk for flooding in the tunnel at Riddarholmen, the road network at Tegelbacken is at risk to be put under water. There is also the, risk for contamination of the drinking water and that the, power stations for central and vital parts of central Stockholm is threatened. Slussen in Stockholm is going to be rebuilt. During this rebuilding not only the channel itself but also he bypass will be rebuilt resulting in an increased drainage capacity from Lake Mälaren to the Baltic Sea. With this increase in drainage capacity the risk of flooding and the subsequent safety risks will be greatly reduced.