ASDST Western Mounds and Shell Pre1750 Model

The Aboriginal Sites Decision Support Tool ASDST extends the Aboriginal Heritage Information Management System (AHIMS) by illustrating the potential distribution of site features recorded in AHIMS.\r\nASDST was first developed in 2012 by the Office of Environment and Heritage (OEH) to support landscape planning of Aboriginal Heritage. The Tool produces a suite of raster GIS modelled outputs and is held in Esri GRID format. The first suite was published in 2016 as Version 7 at 100m resolution and in Lamberts Conic Conformal Projection (LCC). The current Version 7.5 was produced by the now Department of Planning, Industry and Environment (DPIE) in 2020 at 50m resolution in Geographic Coordinate System (GCS). Each layer covers the extent of NSW. \r\n\r\nThe suite of layers includes separate predictive layers for different Aboriginal site feature types. The feature codes used in layer naming conventions are:\r\n\r\n* ALL = model for all feature types combined \r\n* AFT = predicted likelihood for stone artefacts \r\n* ART = predicted likelihood for rock art \r\n* BUR = predicted likelihood of burials \r\n* ETM = predicted likelihood of western mounds and shell \r\n* GDG = predicted likelihood of grinding grooves \r\n* HTH = predicted likelihood of hearths \r\n* SHL = predicted likelihood of coastal middens \r\n* STQ = predicted likelihood of stone quarries and \r\n* TRE = predicted likelihood of scarred trees. \r\n\r\nThe feature models have been derived in two forms:\r\n\r\n* The first form (“p1750XXX” where XXX denotes three letter feature code) predicts likelihood of feature distribution prior to European colonisation of NSW. \r\n\r\n* The second form (“curr_XXX” where XXX denotes three letter feature code) predicts feature likelihood in the current landscape. \r\n\r\nFor both sets of feature likelihood layers, cell values range from 0 – 1000, where 0 indicates low likelihood and 1000 is high likelihood. \r\n\r\nPlease 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. \r\n\r\nAdditionally, there are other derived products as part of the suite. These are: \r\n\r\n* drvd_imp = 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.\r\n\r\n* drvd_rel = 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.\r\n\r\n* drvd_srv = 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.\r\n\r\nFor more details see the technical reference on the ASDST website.\r\n\r\nNB. Old layers with a suffix of “_v7” indicate they are part of ASDST Version 7 produced in 2016. The current models (Version 7.5) do not contain a version number in their name and will continue to be named generically in future versions for seamless access.\r\n\r\nUpdates applied to ASDST version 7.5\r\n\r\nFor all ASDST 7.5 data sets, the resolution was increased from a 100m cell to a 50m cell. All data sets were clipped and cleaned to a refined coastal mask. Cell gaps in the mask were filled using a Nibble algorithm. The pre-settlement data sets were derived by resampling the version 7 pre-settlement data sets to 50m cell size. The present-day data sets were derived from the version 7.5 pre-settlement layers and 2017-18 land-use mapping and applying the same version 7 parameters for estimating the preservation of each feature type on each land-use. For version 7.5, the model reliability data set was derived by resampling the version 7 data set to 50m cell size. Accumulated impact and survey priority version 7.5 data sets were derived by applying the version 7 processing algorithm but substituting the version 7.5 pre-settlement and present-day ASDST models.\r\n

原住民遗址决策支持工具（Aboriginal Sites Decision Support Tool，ASDST）通过可视化展示澳大利亚原住民遗产信息管理系统（Aboriginal Heritage Information Management System，AHIMS）中记录的遗址特征潜在分布范围，对该系统进行了功能扩展。

ASDST由环境与遗产办公室（Office of Environment and Heritage，OEH）于2012年首次开发，旨在支持原住民遗产景观规划工作。该工具可生成一系列栅格地理信息系统（raster GIS）建模输出成果，数据存储格式为Esri GRID。首套成果于2016年以7.0版本发布，空间分辨率为100米，采用兰伯特共形圆锥投影（Lamberts Conic Conformal Projection，LCC）。当前的7.5版本由现已更名为规划、产业与环境部（Department of Planning, Industry and Environment，DPIE）于2020年制作，空间分辨率为50米，采用地理坐标系（Geographic Coordinate System，GCS）。所有图层均覆盖新南威尔士州全域范围。

该图层套件包含针对不同原住民遗址特征类型的独立预测图层。图层命名规范中使用的特征代码如下：
* ALL：所有特征类型合并后的模型
* AFT：石制品的预测存在可能性
* ART：岩石艺术的预测存在可能性
* BUR：墓葬遗存的预测存在可能性
* ETM：西部土丘与贝壳遗存的预测存在可能性
* GDG：磨蚀沟槽的预测存在可能性
* HTH：火塘遗存的预测存在可能性
* SHL：沿海贝冢的预测存在可能性
* STQ：石矿场的预测存在可能性
* TRE：伤痕遗留树木的预测存在可能性

上述特征模型分为两种形式：
* 第一种形式命名为“p1750XXX”（其中XXX代表三位字母特征代码），用于预测新南威尔士州欧洲殖民前的特征分布可能性。
* 第二种形式命名为“curr_XXX”（其中XXX代表三位字母特征代码），用于预测当前景观环境下的特征存在可能性。

两类特征存在可能性图层的单元格数值范围均为0至1000，其中0代表低存在可能性，1000代表高存在可能性。

请注意，该数值代表存在可能性而非概率。存在可能性被定义为一种相对度量指标，用于表示某栅格单元格相较于图层内其他单元格，包含目标特征的相对可能性。

此外，该套件还包含其他衍生产品，具体如下：
* drvd_imp：累积影响模型，通过对所有特征模型的殖民前版本与当前版本的差值求和得到。单元格数值范围为0至1000，其中1000代表高累积影响。
* drvd_rel：预测可靠性模型，基于环境距离算法构建，该算法会分析模型所用变量中的记录遗址密度。
* drvd_srv：调查优先级地图，综合考量了模型可靠性（数据缺口）、当前存在可能性与累积影响。单元格数值范围为0至1000，其中1000代表相较于图层内其他区域的最高调查优先级。

如需了解更多细节，请参阅ASDST官方网站上的技术参考文档。

注：带有“_v7”后缀的旧图层属于2016年发布的ASDST 7.0版本。当前的7.5版本模型名称中不包含版本号，未来版本也将沿用通用命名规则，以实现无缝访问。

ASDST 7.5版本所做更新如下：

针对所有ASDST 7.5数据集，空间分辨率从100米栅格单元提升至50米。所有数据集均经过裁剪与清理，并应用了精细化海岸掩膜。掩膜中的栅格空隙通过Nibble算法进行填充。殖民前数据集通过将7.0版本的殖民前数据集重采样至50米栅格单元尺寸得到。现状数据集则基于7.5版本的殖民前图层与2017-2018年土地利用图件生成，并沿用了7.0版本的参数，用于估算每种特征类型在各类土地利用场景下的保存状况。对于7.5版本，模型可靠性数据集通过将7.0版本的数据集重采样至50米栅格单元尺寸得到。累积影响与调查优先级的7.5版本数据集，通过沿用7.0版本的处理算法，但将其中的7.0版本殖民前与现状ASDST模型替换为7.5版本对应模型得到。