“…Data resources consist of archived data (e.g., basic geographic data, archived historical sensing data, remote sensing images, unmanned aerial vehicle images, RFID data, and video monitoring data) and real-time data streams (e.g., monitoring data for city water, electricity, fuel, and gas supplies) produced by sensing webs. Service resources include geospatial data services built on interoperable standards [15], e.g., the Web Feature Service (WFS) [16] for geographical features, the Web Map Service (WMS) [17] for geo-registered map images, the Web Coverage Service for raster data, the Sensor Observation Service (SOS) [18] for near-real-time sensor observations, the Web Processing Service (WPS) [19] for encapsulating analysis and decision models for smart cities, the Sensor Event Service (SES) [20] for filtering of and subscription to sensor observations (events), and the Web Notification Service (WNS) [21] for message notification. Meanwhile, various public emergencies, such as security incidents, transportation accidents, and accidents involving public facilities and equipment, occur frequently and can result in heavy casualties and economic losses [22].…”