Climate change will bring more precipitation in Northern Europe and Sweden.Increasing precipitation will cause more floods, which will increase landslide risks. Inthe Göta river valley there are high landslide risks due to the thick layer of clay andquick clay present there. The river valley has been the home of numerous industriesfor a long time, which unfortunately have left large areas with contaminated soils alongthe river. The Göta river is the only outlet for Sweden's largest lake, called LakeVänern. With increasing precipitation, the water level of the lake will rise. This willlead to a larger tapping of the lake, to not cause floods around the lake. A largertapping will lead to higher flood and landslide risks in the river valley and thusincreasing the risk for contaminated soils entering the river.This study seeks to provide a comparison of two analyses where flood risk classes andheight above water level, functioning as flood uncertainties, as well as contaminatedsoil criteria are used in one of the analyses but not the other, to see if there is a difference.The study also seeks to show where along the river there are high risk areas inneed for climate adaptation measures to reduce risks.The method used was a multi-criteria decision analysis (MCDA) with the Analytichierarchy process (AHP) technique, to include several criteria in the analysis, pairwisecompare the criteria, and calculate their relative weights. The method was utilizedwith Geographic Information System software and AHP software. The robustness ofthe analyses were controlled by performing a One-Factor-at-a-Time sensitivityanalysis.The result of this study was the findings of four areas with high risk values along theGöta river. Three of those areas were found in both performed MCDA's. The fourtharea was only found in the second MCDA where the three additional criteria wereincluded in the analysis.The conclusion of this study is that the areas with the highest risks in relation to flood,landslide, and contamination risks are located in the localities of Lilla Edet, Älvängen,Sure, Göta, and in the city of Gothenburg. Also, there is a difference in the resultswhen including the three additional factors, another area is highlighted as having highrisks. The method used in this study makes it clear that the usage of five or eight criteriacan produce results that are similar to each other. However, by using eight criteriainstead of five and thus including additional risks that are connected with each other,there is an impact on the result, which becomes more precise.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:hig-44788 |
| Date | January 2024 |
| Creators | Forslund, Linda |
| Publisher | Högskolan i Gävle, Samhällsbyggnad |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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