摘要: |
The project uses GIS techniques and deals with the 45 Swedish towns with more than 20,000 inhabitants 1990. The towns of the Stockholm region are excluded. Digital maps from Karteentrum and population statistics on parcel level from Statistics Sweden are used together with geographical data about public transportation systems, created within the project with support from GIS techniques. The data base and the analyses have been carried out with the programmes ArcInfo and ArcView and the results have been processed in Excel. Two measures to estimate the distances to public transportation lines are used in this study. Each line is buffered with a theoretical real distance of 400 meters(308 meters as the crow flies) and intersected with a coverage with the population informatin on parcel level. The number of inhabitants within the buffer zone is calculated and compared to the total population of the town. The other method is to calculate the distance from every parcel unite within the town to the nearest public transportation line as the crow flies, multiply that distance with the number of inhabitants at the parcel unite and then add all these products for each town. Finally this summary is divided with the total town population and multiplied with 1,3 to correspond to a theoretical real distance. |