SDIs offer access to a wealth of distributed data sources through standardised service interfaces. Recently, also geoprocessing capabilities are offered as services in SDIs. Combining data sources and processing services in service chain enable the generation of information that is tailored to the users needs. In this paper, we present a rule-based description framework and an associated discovery and composition method that helps service developers to create such service chains from existing services. The goal of the description framework is to describe services on a conceptual level rather than closely mir-roring specific implementation details. It consists of a simple top-level ontology as well as a domain ontology, which provide the bas...