Methodology for creating and modifying distributed topologically structured geographical datasets

Sammanfattning: Spatial relationships are a comprehensive and essential part of geographical information management and GIS. Topological relationships are a subgroup of the spatial relationships. They are defined by the fact that they do not break under topological transformations, meaning they remain when stretching, twisting or crumbling the underlying space. Topological relationships are for instance relationships such as contains, crosses and overlaps. There are different ways of representing geographical data, many of which do not take the topological relationships into account. For full support the topological relations need to be stored explicitly, which is done according to a topological data structure. Well-established database have implemented this type of structure in a successful way. When looking to manage the data without any database dependency, the solutions are limited. This study look to find a method for developing a GIS client application for creating and modifying distributed topologically structured geographical datasets. The client application should support being disconnected from any database when worked in. Using an existing topology as a start value, for instance data from a topologically structured database, should be possible. Alternatively, the user should be able to create data from an empty topology. During this study, a client application as the one described above is developed. The product is near complete when compared to the requirements set up. Some weaknesses occur, however they are due to other factors than the pure logic of the topological calculations. A method for developing a topologically structured client application is therefore considered found. The implemented functionality covers basic operations, leaving room for further developments. With the method brought by this study, similar client applications can be developed for other devises including mobile phones and tablets. Furthermore, a general topological library could possibly be developed using the same techniques, which would contribute to better conditions for developing topologically structured services.