Abstract
The increasing availability and variety of large environmental data sets is opening new opportunities for data mining and useful cross-referencing of disparate environmental data sets distributed over a network. In order to take advantage of these opportunities, environmental information systems will need to operate effectively in a distributed, open environment. In this paper, we describe the New Zealand Distributed Information System (NZDIS) software architecture for environmental information systems. In order to optimise extensibility, openness, and flexible query processing, the architecture is organised into collaborating software agents that communicate by means of a standard declarative agent communication language. The metadata of environmental data sources are stored as part of agent ontologies, which represent information models of the domain of the data repository. The agents and the associated ontological framework are designed as much as possible to take advantage of standard object-oriented technology, such as CORBA, UML, and OQL, in order to enhance the openness and accessibility of the system.