Using GIS technology to guide disaster mitigation, disaster relief and post-disaster reconstruction is an important use for GIS applications. In order to confront a catastrophe on the scale of the Sichuan earthquake, Beijing East-dawn Information Technology Co. Ltd developed a set of disaster relief information systems using Skyline’s technology adapted for specific earthquake situations. The system records real-time information of village locations in the affected areas, the location of aftershocks, township deaths statistics and disaster relief efforts. Some of these relief efforts include the distribution of army supplies, transportation and other route information, and the location of damaged bridges and roads. Some of the real-time tracking information provided support for command and control of the disaster relief efforts.
System Architecture
1. Data layer - Data layers include a comprehensive database of disaster information and basic geographic information. Other GIS data include roads, plants, a hydrographic net and residential information from surveying and mapping.
The disaster information database is used for storing data on the earthquake relief process including the location of earthquakes, road conditions, casualties, etc.
The analyses database is used by earthquake disaster operations departments to report characteristics of seismic disaster management information. Specific data are divided into static information and dynamic information. Static information includes disaster relief for personnel, facilities, equipment, etc. Dynamic information includes the rescue plan, position monitoring, etc.
The names and addresses database can generate standard addresses automatically, primarily according to disaster-affected areas, and then the standard address can generate map coordinates to establish the address coding database.
The location information database is mainly used to achieve spatial orientation. In addition to the core database, the data also contain multimedia and historical data.
The multimedia database can store photographs, ichnography, Web, voice, video and data records in order to more fully understand the situation in affected areas; the real-time historical database is mainly used for monitoring a variety of status information.
2. Application layer - The application layer can provide data on spatial information to support relief workers.
3. Service layer - The service layer is based on Skyline’s three-dimensional GIS software, which provides map service, spatial query services, location services, address matching service, access control components and other services. These applications can be easily integrated with the GIS. Simultaneously, the solution can store GPS, video and other data as component layers. It reduces the complexity of the application layer, which can then be more easily integrated with external systems.
System Function
1. Basic mapping operation - Here are the basic mapping functions employed:
- zoom in
- zoom out
- calculating distance, area measurements
- spatial query
- navigation
- indexing in accordance with the provincial, city and county (city, district)
- four town indexing
- display and control of remote sensing images
2. Map information query - The system provides the ability to query property information in two ways. Property queries provide the spatial position of urban areas, villages, roads and disaster information by name, plus the ability to view attribute information at the same time. Querying uses circle and polygon fences to query disaster information, relief supply drop information, population information within the scope of a certain area, and to classify display.
The system helped to collect disaster information from villages, towns and counties. The main functions included collecting seismic information, affected population information (deaths, missing persons, injuries, etc.), housing damage information (number of collapsed buildings, number of damaged houses, etc.), disaster relief information (number of people needing relief, relief supply distribution information) and so on.
3. Dynamic demonstration - The system can symbolize disaster and relief information such as affected range, collapsed houses, collapsed bridges, landslides, mudslide zones, damaged base stations and relief supply drop points on map. It can then organize and manage this information by plotting data in these groups. Then a dynamic demonstration is conducted to simulate how the earthquake disasters happened and the implementation of the rescue plans.
4. Traffic information management - The system can locate and view the real-time traffic conditions of the disaster area such as whether there is any new disaster-related congestion information. This function provides real-time reports to rescuers so that relief supplies can reach the disaster area in a timely manner.
5. Disaster relief information management - The system has a specialized management capability to collect and manage various kinds of information about the disaster area specifically for relief efforts. This function can export information when needed to relevant departments.
6. Disaster relief information statistics output - After collecting and managing the information about the disaster area from all sources, the system can output the corresponding information statistics, so as to provide reliable information at a macro level.
Conclusion
The biggest advantage of GIS is the visual analysis and expression of spatial data especially in three dimensions. Fast and effective collection and the ability to update real-time spatial data are critical. These features will play a significant role in future earthquake emergency relief incidents. However, GIS for this situation requires large amounts of data, especially matching up the spatial data and socio-economic attribute data for disaster relief. Therefore, a sound data network is the key for GIS to play a role in relief events.