National exposure information system for risk assessment
In August 2002 the Council of Australian Governments (COAG) published a review of natural disaster relief and mitigation arrangements for Australia (COAG, 2002). In response to "develop and implement a five-year national program of systematic and rigorous disaster risk assessments" recommendation, Geoscience Australia (GA) has undertaken a series of national risk assessments for a range of natural hazards.
To assist Australia's emergency managers in prevention, preparation, response and recovery (PPRR) to natural hazard impacts, we need nationally consistent exposure information. Fundamental to any risk assessment is an understanding of the exposure including number and type of buildings, infrastructure and people exposed to the hazard of interest. There is no such database or information in existence at a national level to assess the risk consistently across the nation. It is important to emphasise that understanding the risks associated with various hazards requires more detailed information than the population and number of structures at a census district level. The understanding of building type, construction (roof and wall) type, building age number of storeys, business type and replacement value is critical to understanding the potential impact from various hazards.
The development of nationally consistent exposure information requires detailed spatial analysis and integration of available demographic, structural and statistical data. Fundamentally, this system is developed from several national fundamental spatial datasets. Several assumptions were made to derive meaningful information. The National Exposure Information System underpins risk assessment and impact for various hazards like earthquake, cyclones, severe wind, tsunami, flood and critical infrastructure projects. It will be integrated with early warning and alert systems to provide real time assessment of damage or forecast the impact for any plausible hazards. This information system is intended to provide a relative assessment of exposure from combined hazards and demonstrate the geographic distribution of exposure for regional planning at an aggregated census district level now and at a mesh block level in future. More building and socio-economic information will be incorporated as new datasets or sources of information become available. Several initiatives are being considered to source the building level of information from states and local governments.