ASDST Accumulated Impacts

The Aboriginal Sites Decision Support Tool (ASDST) was developed by the Office of Environment and Heritage to support landscape planning of Aboriginal Heritage. The Tool was used to produce a suite of raster GIS modelled outputs - being held in Esri GRID format in this instance. Each layer covers the extent of NSW at a resolution of 1 hectare. The suite of layers includes separate predictive layers for different Aboriginal site feature types. The codes used in layer naming conventions are: ALL = model for all feature types combined; AFT = predicted likelihood for stone artefacts; ART = predicted likelihood for rock art; BUR = predicted likelihood of burials; ETM = predicted likelihood of western mounds and shell; GDG = predicted likelihood of grinding grooves; HTH = predicted likelihood of hearths; SHL = predicted likelihood of coastal middens; STQ = predicted likelihood of stone quarries; and TRE = predicted likelihood of scarred trees. Layers with a suffix of “_v7” indicate they are part of ASDST version 7. The feature models have been derived in two forms. The first form (“XXX_v7”, where XXX denotes three letter feature code), predicts likelihood of feature distribution prior to European colonisation of NSW. The second form (“XXX_c_v7”, where XXX denotes three letter feature code) predicts feature likelihood in the current landscape. For both sets of feature likelihood layers, cell values range from 0 – 1000, where 0 indicates low likelihood and 1000 is high likelihood. Please note the scale is likelihood and NOT probability. Likelihood is defined as a relative measure indicating the likelihood that a grid cell may contain the feature of interest relative to all other cells in the layer. Additionally, there are other derived products as part of the suite. These are: acm_imp_v7 = which is a model of accumulated impacts, derived by summing the difference between the pre colonisation and current version of all feature models. Cell values range from 0 – 1000, where 1000 is a high accumulated impact. mod_rel_v7 = which is a model of the reliability of predictions based on an environmental distance algorithm that looks at recorded site density across the variables used in the models, for more details see the technical reference on the ASDST website. Cell values range from 0 – 2519, where high values indicate larger data gap and consequently, lower model reliability. surv_pri_v7 = which is a survey priority map, which considers model reliability (data gap), current likelihood and accumulated impact. Cell values range from 0 – 1000 where 1000 indicates highest survey priority relative to the rest of the layer.