Geographic information systems (GIS) ans spatial information systems (SIS)
It is possible that geographic information systems (GIS) or spatial information systems (SIS) will be the future of hazard mapping. A GIS/ SIS is essentially a computer program that combines a relational database with graphic interpretation and output. It is possible to enter a variety of types of data, and relate them through formulae, or overlap them in a graphic presentation, either on screen or as a printout.
GIS/ SIS allows the rapid analysis of large quantities of related data, and can also be used as a predictive tool. When applied to hazard information, GIS/ SIS can be used for prevention, mitigation, preparedness and response.
An example of the use of GIS/ SIS in preparedness and response is in the recording and analysis of data on large storages of hazardous materials. Many government agencies collect data on these storages for the purposes of licensing and public safety. If the data is entered into a GIS/ SIS it is possible to rapidly display graphically:
- where the largest storages are;
- where storages are adjacent to sensitive land uses such as residential areas;
- where there are storages adjacent to each other, an accident in one of which may affect the other;
- distances to the nearest fire station;
- who owns a particular storage and what their after hours contact details are;
- what material is stored in the area, and where on the site the material is stored;
- etc.
It is also possible to combine the GIS with a gas or smoke modelling program to determine the possible concentrations of gas, fumes or smoke following an accidental hazardous material release or a fire. The shortest routes from a given fire station to a given storage can be calculated, and possible evacuation routes can be plotted.
This information can be used both for emergency planning in relation to the storage of hazardous materials, and in the response to hazardous materials accidents.
GIS/ SIS can thus combine data on:
- the community;
- vulnerability;
- hazard characteristics; and
- the environment;
to develop valuable emergency management information.
