Addressing the urban heat island effect in Stockholm : An analysis of its presence and relation to land cover and urban planning

Sammanfattning: As urbanization and global warming increase, an increasing importance is set on that urban planning processes take the possible effects of urban heat islands into account. In order to provide local city planners with site specific knowledge of the current situation in Stockholm, this study has explored the intra-urban heat island effect in Stockholm municipality by identifying major problem areas as well as addressing the statistical relationship between temperature and factors relating to land cover and urban planning strategies. Remotely sensed land surface temperature (LST) and the Swedish National Land Cover Database (NMD) have formed the data basis for the analyses that were carried out using GIS. The LST and land cover information have been extracted from randomly placed circle polygons in order to create a sample for the statistical analyses.  The results show that there exist differences in temperature within Stockholm municipality, both within the municipality as a whole and between various urban characters. In both cases, land cover is identified as an important, but not sole, factor to explain the differences. On land areas, artificial non-vegetated surfaces and forest is identified as the land cover classes of most relevance when it comes to the urban heat island effect. For both land cover classes, a strong correlation to LST is seen. Even though certain uncertainties and limitations are embedded in the data as well as in the method choices, the study can conclude in that the urban heat island effect is present in Stockholm municipality and that it can be derived from both land cover and urban characters.