Vector data are spatial data in the form of x, y coordinates. Each feature has a
coordinate or a set of coordinates to refer to a particular location within a specific
positional referencing system (Tomlin, 1990). Spatial objects are thus defined by points,
lines and polygons, in a similar way to conventional paper maps and drawings. A vector
data format can provide a flexible and accurate representation of an object due to the fine
resolution obtainable with coordinate points. Vector structures also tend to incorporate the
topology and other spatial relationships between the individual entities and are therefore
ideally suited to representing linked networks such as pipe or road systems. It is very
accurate for the measurement of areas or lengths Every feature of the vector structure
carries its ID number to which the attribute information is assigned. Computer data storage
is very economical but certain operations such as overlay analysis and proximity
calculations have high computational requirements, which result either in slow operations
or high hardware specification requirements. Typical examples of vector data format are
results of map digitalization or GPS collected data.