Flow category landslide susceptibility modelling of the Sydney Basin

The University of Wollongong Landslide Research Team has completed a GIS-based Landslide Susceptibility model for the entire Sydney Basin region. According to the Australian Bureau of Statistics and the 2011 Census data, the population within the Sydney Basin Study area is approximately one quarter of the population of Australia. This model has been developed with the aid of a large scale Landslide Inventory for NSW, which contains 1823 landslides to date. A composite geology dataset has also been developed using commercially available geology datasets including those from NSW Department of Primary Industries and elsewhere. The model employs a 10m pixel Digital Elevation Model (DEM) across the entire study area derived from either Local Government sourced Airborne Laser Scan data or the 30 m pixel year 2000 Shuttle Radar Topography Mission (SRTM) data. Using techniques developed over the last decade and refined ArcGIS tools developed over the last three years, Data Mining methods and ESRI ArcGIS capabilities have enabled the modelling to produce a very useful zoning outcome over the entire Sydney Basin area. The major advantage of this new tool is that it applies the See5 logic derived from rule sets over a large datasets, and produces a visually interpretable outcome. The authors expect the susceptibility zoning to be suitable for use at Regional to Local Advisory level Local Government Planning Development Control Plans.