Urban flood risk mitigation : A perspective form urban planning

Abstract: Due to the global warming and climate change, an increased frequency of high intensity rains and other disasters are expected all around the world. To predict this change in climate the IPCC has created a set of climate scenarios, RCPs, that will try to predict the future climate based on how much we are able to adapt and mitigate the effects we as a species have on the environment. This master thesis will seek to explore the possibility to use urban planning tools to help mitigate the increased effects and sizes of floods due to the global warming. To achieve this, a case study of Luleå is done, where urban indicators are used to improve the resilience of the city. This is combined with a policy study to see how Luleå compare to other cities in their policies that affect flood protection and mitigation. To have a strong flood protection system in a city several factors need to be considered. One of the biggest factors is what type of strategy is chosen. One possible strategy is resilience, this combines seeming paradoxes into a working flood protection and mitigation plan. Resilience improves the flood protection and mitigation by combining and improving the robustness, adaptability, and transformability of the city. This is done by, among other things promoting inter disciplinary cooperation, public cooperation and knowledge of flooding, and promoting the use of water in the city as an asset. Blue and green infrastructure could also be implemented into the city as these measures help improve the resilience of a city in many regards. Not just for flood protection, but it can also help mitigate the effects of droughts or heatwaves and improve the general wellbeing of the citizens. In the policy study it was found that different cities varied in both scale and strategy in their flood protection measures. All the cities that were looked at would also need to increase the scale of their protection and mitigation measures to mitigate the increased size and frequencies that the climate change brings. In Sweden, especially in the northern parts, the increased risk is not as high as in other parts of Europe. This is due to the land rise in Sweden mitigating the sea level rise. In Luleå the sea level and land rise are expected to fully mitigate each other until the year 2100. The policy study also showed that a history of flood related disasters did not necessary guarantee a strong flood protection scheme, but it would increase the probability of one. In the case of Luleå, the city has mostly focused on flood proofing buildings and infrastructure in the high-risk areas or those who are seen as critical to the society. Based on the analysis of the policies and indicators that were developed for Luleå, the city seems to have good protection from the current risks, such as a 100-year flood, flow, or rain. But the systems in place will most likely need to be expanded and developed further to mitigate the rising risk due to global warming. Some measures that can be implemented are related to the adaptability and transformability, like brochures that teaches the public about flood-protection and what to do and how to act in case of a large flood in the city.