Design And Implement A WebGIS-Integrated Hydrological Monitoring System

With the development of science and technology, advances in science of technology lead to new requirements in hydrological monitoring. The application of 3S technologies (Remote Sensing, Geography Information Systems, Global Positioning System) in hydrologic monitoring can help improving work efficiency and quality. Nowaday among the common WebGIS-integration solution, the commercial WebGIS solutions are expensive and require users'professional knowledge and skills in building geographical spatial database, while the free Internet Map services (e.g. Google Map) have little ability in spatial analysis and cannot guarantee user data security.Considering the current status of users' network infrastructure and professional skills, a low cost and easy-to-use WebGIS platform is proposed which utilizes open source software and free GIS resources, such as OpenLayers, an open source JavaScript framework, and GeoServer, an open source GIS server.resources are integrated from the National Geographic Information Public Service Platform via the Tianditu Map service. By carefully organizing the network structure, the proposed WebGIS platform reduces dependency on Internet and ensures user data security to a certain extent. First a contour surface service is implemented, which generates a contour surface image based on IDW algorithm and slices it into tiles according to pyramid model theory. Then a GeoServer plug-in is developed which follows WMTS (Web Map Tile Service) standard. It responds to request from the client for title maps and works in collaboration with the contour surface service to complete contour surface generating and displaying. Both of the contour surface service and the GeoServer plug-in are finally integrated into the system to provide the full functionality of hydrological monitoring.The actual running of the WebGIS platform in real-world scenarios demonstrates its spatial analysis ability, low cost and low Internet dependency, free of construction and maintenance of a geographical spatial database. Features of the hydrological online monitoring system based on the Web GIS platform include:the station's basic information, real-time rainfall and water information, scene image, water-level line chart, map service, rainfall distribution, and supporting query through mobile terminals. It achieves its designed goal, offers an economical solution for small and medium-sized hydrological monitoring department, and reduces the cost of construction and operation.