ABSTRACT
Geographical information systems are currently with notable challenges applications in environmental modclling and management. These applications are
characterized large heterogeneous spatiotemporal datasets involving many variables . The spatial data infrastructure is often a subject-oriented collection of framework data as well as field data (Goodchild, 1 996) used for a variety of monitoring and decision-support purposes. In these circumstances , supportive computing frameworks are needed to under pin spatiotemporal research in an exploratory and intuitive manner (Ahlberg, 1 996; Dcnsham, 1 994; Mesrobian, 1 996). other requirements, the computing framework should allow:
fillThe user to deal with natural representations of the phenomena and relationships of interest.
