This chapter describes an algorithm for the input of vector-topological data to parallel GIS operations such as vector-polygon overlay and vector-to-raster conversion of non-overlapping classified polygons. In parallel geographical information system (GIS) operations, there is an additional overhead since the input data must also be distributed to parallel processes. In GIS operations such as polygon overlay, where attribute values and the spatial description of geographical features are manipulated, it is the coordinates of the polygon boundaries and the left and right attribute values at these boundaries that are required by the underlying algorithms. Line intersection tests are required in operations such as polygon overlay, topology creation and buffering. Some of the techniques used to improve line intersection algorithm performance require spatially sorted data. The polygon overlay and vector-to-raster conversion operations require the spatial coordinates of the boundaries of the features and the attribute values on the left and right side of these boundaries.