Mapping and Analyzing Sand Dunes in Norrbotten, Sweden: GEOBIA-Based Identification and the Spatial Relationship to Glacial Landforms

• Main Author: Högberg, Cornelia
• Format: Bachelor Thesis
• Language: English
• Published: Uppsala universitet, Luft-, vatten- och landskapslära 2024
• Subjects: sand dunes; geomorphological mapping; GEOBIA; palaeowind reconstruction; landscape devlopment; sanddyner; geomorfologisk kartering; vindrekonstruktion; landskapsutveckling; Physical Geography; Naturgeografi; Arctic; Pajala; Torra; Climate change; Norra Sverige; Northern Sweden; Norrbotten
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-538521

The ongoing climate change makes it vital to understand processes that control the complex climate system and get better insights into future predictions. The Arctic dunes in northern Sweden carry information about the climatic agents forming the dunes and the dune activity during the Holocene. Past climate of this area is significant to understand due to the anthropogenic effects on climate and Arctic amplification, the fast pace of warming in the Arctic. Mapping of Arctic dunes allows for a deeper interpretation and understanding of regional Holocene climate, and palaeowind reconstructions can be made by observing dune properties. The identification of the dunes was done using geographic object-based image analysis (GEOBIA), a semi-automatic mapping that allows the mapping of large areas. This was done using the software eCognition Developer 10.2 where DEM, slope, and curvature data were used as input for the analysis. The following classification of the dunes was done by developing a rule set based on the characteristics of the dunes. The mapped dunes are primarily parabolic indicating prevailing winds from the northwest. The dunes have been located close to or superimposed its possible source material, like eskers and glaciofluvial deposits, which correlate with the inferred wind direction. Sanddyner är karaktäristiska för varma och torra klimat nära ekvatorn, men de förekommer även i norra Sverige. Att undersöka och tolka sanddyners förekomst kan ge en förståelse för det klimat som rådde under dynens bildning, i detta fall efter den senaste glaciationens slutskede. Detta är intressant ur ett klimatperspektiv, där sanddyner agerar som ett klimatarkiv eftersom de bevarats på grund av vegetationen som stabiliserar den. Sambandet mellan sanddyner och det omkringliggande landskapet är även intressant då landskapet runt Pajala i Norrbotten har präglats av flera nedisningar där effekten av istäcket är synligt. Under fasen av issmältning bildas olika landformer, bland annat rullstensåsar ...