This attribute describes zoning requirement for new buildings to be constructed to comply with AS1170.2 Wind Actions. Each address in Australia in iLEAD has been classified in accordance with the AS1170 wind code zone that it sits within geographically.
AS1170 identifies regions within Australia that are likely to experience cyclonic winds of different strengths. Builders are required to construct buildings in each of these different zones in a manner that prevents building failure in the event of the defined cyclonic wind speed being reached.
Wind load calculations are complex and highly specific to individual building sites. iLEAD uses each declared wind zone region as an exposure proxy for the quantum of wind speed anticipated, it is not absolute and should not be used as the final assessment of potential wind load for a location, it is indicative only.
Tropical Cyclone Average Return Interval
This iLEAD attribute stratifies address level exposure according to the historical occurrence of cyclone events within 50km of the address, expressed as an Average Return Interval.
Address level ARI data has been calculated through an intersect of the centroid of each Australian address with a 50km buffered polyline, with each polyline representing a cyclone track that has occured in the last 100yrs.
Exposure to Riverine Flooding
This iLEAD attribute describes the flood frequency at which the address is first expected to be exposed to a riverine flood event.
This attribute is calculated using government supplied geospatial data, overlapped with GNAF centroid coordinates for each address in Australia.
More detailed data, including calculated depth information, is available in the ICA's National Flood Information Database and Flood Exclsuion Zone dataset, for license holders.
Potential Bushfire Exposure
This iLEAD attribute describes the potential bushfire exposure based upon either designated BushFire Prone Land (BFPL) or distances from vegetation. It is not based on Bushfire Attack Level (BAL) which requires a highly specific calculation based upon multiple factors for an individual site.
This proxy exposure information should only be used to determine if you should make further and more detailed inquiries as to the precise bushfire risk at a location, after taking into account all BAL factors including slope, orientation, vegetation type etc.
Earthquake Damage Exposure
This iLEAD attribute provides a proxy exposure to earthquake damage by referencing the Spectral Period zones referenced in the National Construction Code.
The higher the Spectral Period for a zone, the higher the earthquake resilience required for designated buildings and infrastructure.
This is a proxy for earthquake exposure only.
Exposure to Damaging Hail
This iLEAD attribute stratifies the expected frequency of damaging hail events (stones larger than 5cm), based upon historical thunderstorm data (postcode level) measuring vertically integrated water, combined with observational data to estimate the return interval of damaging hail.
This iLEAD attribute stratifies the relative intensity of rainfall in a given location for a 60 minute duration 1% AEP rainfall event. The location in Australia with the largest rainfall for this defined event is used as a the benchmark for 'extreme rainfall'.
This data was created using gridded (10km) intensity frequency duration (IFD) data, created for the Australian Rainfall & Runoff 2015 model. All GNAF coordinates falling within each 10x10km grid square have been given the same extreme rainfall designation.