ASDST Scarred Trees Current 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，简称ASDST）通过可视化展示原住民遗产信息管理系统（Aboriginal Heritage Information Management System，简称AHIMS）中记录的遗址特征潜在分布范围，扩展了AHIMS的功能。
ASDST于2012年由环境与遗产办公室（Office of Environment and Heritage，简称OEH）首次开发，旨在为原住民遗产景观规划提供支撑。该工具可生成一系列栅格地理信息系统（Geographic Information System，简称GIS）建模输出成果，数据格式采用Esri GRID格式。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，简称LCC）。当前的7.5版本于2020年由规划、产业与环境部（Department of Planning, Industry and Environment，简称DPIE）制作，空间分辨率为50米，采用地理坐标系（Geographic Coordinate System，简称GCS），所有图层均覆盖新南威尔士州（NSW）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，图层命名规则中使用的特征代码如下：
* ALL = 全特征类型合并模型
* AFT = 石制品预测似然
* ART = 岩画预测似然
* BUR = 墓葬预测似然
* ETM = 西部土丘与贝壳堆积预测似然
* GDG = 研磨凹槽预测似然
* HTH = 灶坑预测似然
* SHL = 海岸贝丘预测似然
* STQ = 石料采石场预测似然
* TRE = 痕木（划痕树木）预测似然

上述特征模型分为两种形式：
* 第一种形式为"p1750XXX"（其中XXX代表三位特征代码），用于预测新南威尔士州欧洲殖民之前的遗址特征分布似然。
* 第二种形式为"curr_XXX"（其中XXX代表三位特征代码），用于预测当前景观中的遗址特征分布似然。

两类特征似然图层的栅格单元取值范围均为0至1000，其中0代表低似然，1000代表高似然。

请注意：本数据集的度量标准为似然（likelihood）而非概率（probability）。似然的定义为：相对度量指标，用于表征某一栅格单元相较于图层内其他单元，包含目标特征的可能性高低。

此外，该套件还包含以下衍生产品：
* 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。栅格单元取值范围为0至1000，1000代表累积影响程度较高。
* drvd_rel：预测可靠性模型，基于环境距离算法构建，该算法会统计模型所用变量对应的已记录遗址密度。
* drvd_srv：调查优先级地图，综合考量模型可靠性（数据缺口）、当前似然值与累积影响程度。栅格单元取值范围为0至1000，1000代表相较于图层内其他单元，调查优先级最高。

如需了解更多细节，请参阅ASDST官方网站上的技术参考文档。

备注：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版本更新内容：
针对所有ASDST 7.5数据集：
1. 空间分辨率从100米栅格提升至50米栅格；
2. 所有数据集均经过裁剪与清洗，生成精细化海岸掩膜；
3. 掩膜中的栅格空白区域通过Nibble算法进行填充；
4. 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米栅格尺寸得到；
5. 当前景观数据集基于7.5版本的殖民前图层与2017-2018年土地利用图生成，并沿用7.0版本的参数，用于估算各类特征在不同土地利用类型下的保存状况；
6. 7.5版本的模型可靠性数据集通过将7.0版本数据集重采样至50米栅格尺寸得到；
7. 7.5版本的累积影响与调查优先级数据集通过沿用7.0版本的处理算法，但将输入替换为7.5版本的殖民前与当前景观ASDST模型得到。