Manipulation tools may operate upon this, enabling relationships and conclusions to be found. Spatial data and spatial analysis is required by towns, cities and their planners so detailed information about the distribution of land and resources are known. For example, civil engineers need to plan the routes of roads, canals and other transportation networks, police departments need to know the spatial distribution of various kinds of crime, the fire brigade requires the quickest routes from the station to certain suburbs, local councils the land sizes and occupancy information, medical organisations the distribution of sickness and disease, and commercial interests the location of sales outlets and potential markets. To the right is a picture that displays the connection of a GIS database and the related fields that are employed to overcome technical and conceptual problems. Model Vector Models Vector models store objects that lie in space.
Spatial primitives allow all positions, lengths and dimensions of an object to be defined precisely.
They may indicate spot heights, oil wells, post offices, drill holes, dwellings etc. They may indicate roads, drainage, railway lines, electric cables, sewage pipes etc. A multi-sided shape that represents an area on a map. They may indicate states, counties, pastures, shopping centres, landuses etc. Alternate terms for a polygon include areas, regions, rings and closed loops.