National Exposure Information System (NEXIS)
The National Exposure Information System (NEXIS) is a unique capability designed to provide comprehensive and nationally consistent exposure information to enable users to understand exposure of the Australian built environment to natural disaster.
Geoscience Australia embarked on the development of NEXIS in response to the Council of Australian Governments (COAG) reform commitment on Australia's ability to manage natural disasters and other emergencies. The COAG commitment was for the establishment of a "nationally consistent system of data collection, research and analysis to ensure a sound knowledge base on natural disasters and disaster mitigation" (DOTARS 2002).
NEXIS was designed to provide nationally consistent exposure information for regional or national impact analyses. In its current form it is not intended to provide local-level analysis involving individual buildings, which needs more specific information about the exposure to estimate risk at such small scales.
- NEXIS currently maintains information about residential, commercial and industrial buildings - this data enables research and analysis which presents a "snapshot" of the exposure of the built environment to natural disasters;
- NEXIS uses publicly available data about buildings, demographics, economic information, surveys and statistical analysis to derive exposure information;
- Exposure information can be aggregated to standard geographic areas such as Local Government Areas and Statistical Areas for decision makers;
- Exposure information can be modelled for various hazard scenarios such as sea level rise under particular climate conditions or using disaster footprints with severity zones;
- Exposure information can also be aggregated based on user-defined areas. More information about this service can be provided by contacting the NEXIS team.
Future development of NEXIS will include: type of businesses and financial turnover, number of employees, institutions (education, health, community halls, stadiums etc.), agriculture, essential infrastructure and transport.
The exposure information available from NEXIS includes:
- Aggregated Location: buildings are captured from a variety of sources including Geoscience Australia’s 1:25 000 rural building topographic data capture program, state and local government building surveys and databases. In absence of specific data, Public Sector Mapping Agencies' Geocoded National Address Framework (GNAF) and cadastral data are used to assist the probable location of buildings.
- Building Usage: building use is defined as residential, commercial and industrial. Specific land use datasets at local, state and national levels are used to define building level use.
- Building Construction Type: the type of residential dwellings are separate house, semi-detached and apartments, two storey, three storey and four storey plus. Residential buildings also consist of a roof and wall material description. Commercial and industrial buildings include a series of defined construction types including timber, masonry, concrete and steel construction. The year of construction is also maintained at the building level. Sample data sourced in these areas are used to populate the construction parameters to the entire building stock. Where this information is not known, settlement and climatic zones, and building codes help determine the relevant construction materials for each building.
- Building Replacement Value: replacement value is the cost to rebuild the same type and sized building with the same materials using current standards but does not include market value and land value. Residential buildings also have a contents value that is derived from statistical approximations. Building cost factors were sourced from quantity surveyors to derive the replacement value of the building based on its region and quality.
- Demography: demographic information is maintained at the household or dwelling level including income, tenure status, people aged less than five and over sixty five years of age, single parent families, those without access to a motor vehicle, those with limited English language skills in the home, those requiring assistance, those who volunteer, and those who have moved in the past one to five years. (This information is derived from Australian Bureau of Statistics - Census Data).
The exposure information is aggregated for standard geographic areas such as Australian Bureau of Statistics - Local Government Areas and Statistical Area 2 (SA2) is available to download.