Accessibility to green area qualities in the Stockholm region and their possible correlations to property values : A GIS-based network analysis

Sammanfattning: The concept of accessibility has in recent years been more used in urban planning, where access to urban services and attractive places, such as green areas, is desirable. In a rapidly growing city region like Stockholm, accessibility is especially important in order to provide an attractive and sustainable region. Several studies have supported the positive correlation between green areas, human well- being and sustaining a good quality of life. However, it is rather the qualities possessed by a green area that is attractive and not necessarily the space itself. Moreover, access to green areas is considered to affect the property values and can further indicate whether a green area quality is demanded or not since it may differ depending on the green area type and its quality. Although studies concerning accessibility to green areas and the correlation to property values already have been conducted to some extent for Stockholm, the combination of qualitative green areas have not been extensively researched for the entire region with a network analysis approach. The purpose of this study is to measure the accessibility to green area qualities within the Stockholm region and further assess whether the measured distances correlate with the property values within the region. In this thesis, four green area qualities are selected, based on experience values, which are: Spacious, Quietness, Parks and Protected areas for biodiversity. These green area qualities are considered to contribute to individual’s quality of life, but for their usefulness from a regional planning perspective, a combination of different qualities could have been more attractive. The access is further measured from each dwelling in the Stockholm region to these green area qualities, via the pedestrian road network, for different geographical divisions within the region. These four divisions are: Archipelago areas, Urban countryside areas, Countryside areas and Urban areas. The accessibility analysis is conducted by using a GIS-based network analysis. The correlation between the measured distances and the property values per area is determined by using the Pearson correlation method. The results show that the access to spacious green areas generally is at least good in the entire region, while the access to quietness and protected areas for biodiversity generally is poor. The access to parks is only measured for Urban areas, due to limited mapping, and the results show that a majority have at least good access. Also, the results show that dwellings generally have best access to spacious green areas, while they have poorest access to quietness within the entire region. Dwellings located in the outer parts of the Urban areas had poorer access to Parks than in the more central areas. Moreover, the results indicate that there are differences in access for different geographical divisions within the region and it can be concluded that Urban areas have generally poorer access than the more rural areas. It is found that all different datasets have a positive correlation between the measured distance and the property values per areal, which means that dwellings located far away from these green area qualities have higher property values. The exceptions were for the green area quality: Parks, in Urban areas, and the green area quality: Protected areas for biodiversity, in Urban countryside areas, which instead had a negative correlation. Basically, this means that these dwellings located close to parks in Urban areas and close to protected areas for biodiversity in Urban countryside areas have higher property values. The study further shows that the correlation between all datasets is weak. These weak correlations are however assumed to be affected by other location factors that may have directly opposite correlations to these green area qualities, such as access to the city center, public transport and other urban services. However, all correlations in this study are found to be statistically significant, which mean it can be concluded that a true correlation exists, although it is weak. For the statistical results to be more useful from a regional planning perspective, other location factors could be analyzed as well, in order to get a better understanding of the statistical results. Finally, the results from both the accessibility analysis and the statistical analysis can be used as a basis for future planning and as a spatial decision support to sustain a good quality of life within the Stockholm region.