Web Services for GIS Related Work in Integrating Service Descriptions

Integrating multiple geographic services from different information communities and spatiolinguistic regions is challenging because of its inherent complexity and heterogeneity. A geographic information systems workflow approach can use semantic and syntactic service descriptions to form service chains that can integrate service discovery, composition, and reuse. Service chaining links remote geographic services to help expert users form complex geoprocessing services and perform timely analysis of geodata. This method facilitates the use of XML-based service description languages to build a geoservice-reuse architecture based on common ontologies and shared service descriptions. T he geographic information systems (GIS) field has been highly influenced by advances in Web services technologies. The result is a proliferation of specialized geographic services that, for example, help visualize vector carto-graphic data, locate a map view given a toponym (geographic name), and more recently, provide specific geoprocessing functions. Historically, desktop GIS work-flow has required complex manual data sourcing and reformatting before arriving at even the simplest analysis, such as visualizing geodata themes in context to find spatial relationships between factories and schools. To avoid the common practice of downloading and processing massive data sets using traditional desk-top GIS, the field is now challenged with finding a way to integrate multiple geographic services, each from a specific information community and spatiolin-guistic region. Access to chains of remote geographic services promises more flexible , just-in-time analysis of geographic data that can be updated in situ. In practice, however, chaining geographic services is nontrivial, mostly because geographic data have varied differences from other types of data. (See the " Why Geoinformation Is Special " sidebar for full details.) In this article, we address the unre-solved research topic of semantics and dynamic service chaining. 1 We've developed a methodology that combines ser