Case Study : Geospatial Processing Services for Web based Hydrological Applications

River discharge is an important issue to be monitored because of its significant influence on environmental systems, on human lives for water resource exploitation, and hazards related to floods and landslides. In this context, we have designed and developed a web-based Geoportal for hydrological applications that integrates geospatial processing services and web mapping viewers to provide an interactive and user-friendly interface to hydrological modelling experts and scientists. The server side provides hydrological model logic through a library of distributed geospatial processing services that prepares and presents all geospatial data –satellite imagery, cartography, digital elevation models, and sensor measurements– necessary for running the hydrological (river runoff) model .The Geoportal’s client side facilitates catalogue service searching for appropriate geospatial data, interacts with the geoprocessing services according to the hydrological model parameters, and displays the results into a web mapping viewer by using the Google Map API to provide quick feedback to scientists about the status and behaviour of the hydrological model. This chapter provides an overview of the proposed Geoportal by integrating standards both for geospatial processing services and for geospatial data visualization. We emphasize the challenges and problems encountered during implementation regarding the interoperability of different geospatial standards and components.