SLEWS: DEVELOPMENT OF A GEOSERVICE INFRASTRUCTURE WITH INTEGRATED REAL TIME SENSOR DATA AS A BASIS FOR EARLY WARNING SYSTEMS EXEMPLIFYING LANDSLIDES

Accessible geographic information becomes more and more important for decision making. Spatial data infrastructures (SDI's) allow the distribution of sensor and geographic data and access by using Web Services of the Open Geospatial Consortium (OGC).

Sensor based Landslide Early Warning System (SLEWS) is a joint project of the RWTH Aachen University, University of Rostock, BGR Hannover and ScatterWeb GmbH Berlin that uses open Web Services and the Sensor Web Enablement of the OGC to establish a monitoring and warning system for landslides. SLEWS is build up on a self-organizing wireless sensor network to get real time data.

The Sensor Web Enablement offers different services to access, analyse and to process sensor data which allow an effective data management. One major requirement of early warning systems is to extract immediately reliable information from the collected data. This translation takes place in the information tier by data modelling which involves complex series of algorithm and analytic processes.

In the case of a critical event OGC Services like Sensor Alert Service (SAS) and Web Notification Service (WNS) will sent automatically a warning message. The markup language SensorML is used to formalize the sensor processes. The Sensor Services can be combined with already existing Web Services like the Web Feature Service (WFS), Web Coverage Service (WCS) and Web Map Service (WMS). In the event of long-termed forecast for instance lead time digital maps can support the resource planning. Moreover, within a SDI the functions of classical geoinformation systems can be used by the Web Processing Service (WPS). This allows the intersection of themes, detailed and visualized information about streets, buildings or other critical infrastructures inside the hazard zone. The geographic and sensor information can be made available via an internet browser or other mobile applications like PDA or smartphone.

The development of a SDI with OGC Web Services is an innovative technology that meets the requirements of an early warning system. It is able to encapsulate heterogeneous data and to transform measured data in relevant information. OGC Web Services (OWS) and Sensor Web Enablement (SWE) open up new possibilities in real time monitoring and provide information for decision making by enabling the user to collect data stored in different locations.