ABSTRACT

Current Geographic Information Systems (GIS) are modelling static spatial situations. Using Sinton’s terminology (Sinton, 1978), they hold time constant and then either vary theme or location-depending if they are vector (object) or raster (field) oriented (Frank, 1990; Goodchild, 1990). The world in which we are interested is in constant change; nothing is ever stable. This has been observed by the Greek philosophers and identified as one of the chief difficulties in understanding the world. We need to identify objects that we can see as (relatively) stable and against which we can compare others.