Account-ready data: ecosystem site condition in the Murray-Darling Basin. A data collection from the Regional Ecosystem Accounting Pilot projects

This collection comprises account-ready data for ecosystem site condition in the Murray-Darling Basin, developed in the ‘Ecosystem Accounts for the Murray-Darling Basin’ project, one of two Regional Ecosystem Accounting Pilot (REAP) projects delivering ecosystem accounts at sub-national scales. Dataset values (index) vary continuously from a theoretical minimum of 0.0 (ecosystem integrity extinguished) to a maximum of 1.0 (ecosystem integrity in reference condition). The index represents the contribution that a given site (grid cell) makes to the effective area of habitat remaining within any given spatial reporting unit, expressed as a proportion of the contribution made by a site in reference condition. Ecosystem site condition data are provided for 18 annual epochs (2001 to 2018) derived from the Habitat Condition Assessment System (HCAS), as a modification of version 2.1. The modifications resulted in HCAS version 2.2 of the base model and annual epochs (unpublished national dataset). The supplementary metadata provided with this data collection details how HCAS version 2.2 was derived, and the subsequent processing steps for incorporating landscape context effects, which resulted in ecosystem site condition data for the Murray-Darling Basin version 1.0 (ESC-MDB v1.0). In addition to the core collection, annual change in ecosystem site condition is provided for the years 2002 to 2018. Supplementary data are provided to support interpretation and use. These include the annual time series of Moderate Resolution Imaging Spectroradiometer (MODIS satellite) remote sensing variables used as inputs to the HCAS v2.1 model; the two sub-indexes: HCAS v2.2 habitat condition and inferred local pressures; overall HCAS v2.2 best estimate of ecosystem site condition for the 2001–18 remote sensing epoch and sub-indexes; the trend in ecosystem site condition from the 18 annual epochs and its significance; an analysis of how ‘nearby’ and relevant the 20 reference sites used as benchmarks were to the estimate of condition for each site of interest; and a spatial mask for use when aggregating ecosystem condition data into accounts and tables for reporting to exclude areas identified as potentially erroneous. All raster data in this collection are provided as 100 m spatially-registered GeoTiff files, mostly in floating point format (spatial extent in GDA2020, Australian Albers, EPSG:9473: xmin: 595000, xmax: 1978000, ymin: -4187000, ymax: -2742000). These were used as a basis for developing a set of ecosystem site condition stock accounts and supplementary tables for the Murray-Darling Basin (see the data collection of experimental ecosystem accounts for the Murray-Darling Basin (Schmidt et al. 2023, https://data.csiro.au/collection/csiro:57033).Lineage: See the Supplementary metadata statement included with this collection in the Supporting Documentation section or in the top directory of the data files in this collection.

本数据集集合包含墨累-达令盆地（Murray-Darling Basin）的生态系统场地状况可直接用于生态系统核算的数据，由「墨累-达令盆地生态系统核算」项目研发，该项目是两个旨在开展亚国家级尺度生态系统核算的区域生态系统核算试点（Regional Ecosystem Accounting Pilot, REAP）项目之一。
数据集的核心指数取值为连续区间，理论最小值为0.0（代表生态系统完整性完全丧失），理论最大值为1.0（代表生态系统完整性处于参照状态）。该指数代表给定场地（网格单元）对任意指定空间报告单元内剩余有效栖息地面积的贡献占比，该占比以参照状态下单一场地的贡献值为基准进行折算。
本数据集的生态系统场地状况数据基于生境状况评估系统（Habitat Condition Assessment System, HCAS）生成，覆盖2001至2018年共18个年度时段，为该系统2.1版本的改进版本。本次改进将基础模型升级为HCAS 2.2版本，并生成了对应年度时段的未公开国家级数据集。
本数据集配套的补充元数据详细说明了HCAS 2.2版本的构建过程，以及后续融入景观背景效应的处理流程，最终产出墨累-达令盆地生态系统场地状况数据集v1.0（ESC-MDB v1.0）。除核心数据集外，本集合还提供了2002至2018年的生态系统场地状况年度变化数据。
此外还配套了辅助解释与应用的补充数据，具体包括：用作HCAS v2.1模型输入的中分辨率成像光谱仪（Moderate Resolution Imaging Spectroradiometer, MODIS）卫星遥感变量年度时间序列；两项子指数：HCAS v2.2生境状况指数与推断局部压力指数；2001-2018年遥感时段内HCAS v2.2对生态系统场地状况的最优估算结果及对应子指数；基于18个年度时段的生态系统场地状况变化趋势及其显著性；针对各目标场地的状况估算值，分析作为基准的20个参照场地的邻近性与相关性强弱；以及将生态系统状况数据聚合为核算报表与统计表格时，用以剔除疑似错误区域的空间掩码。
本集合内的所有栅格数据均采用100米空间配准的GeoTIFF格式存储，多数为浮点型格式，空间参考采用GDA2020澳大利亚阿尔伯斯投影（EPSG:9473），范围为xmin: 595000, xmax: 1978000, ymin: -4187000, ymax: -2742000。上述数据可作为构建墨累-达令盆地生态系统场地状况存量核算表与补充统计表的基础，相关内容可参考《墨累-达令盆地实验生态系统核算数据集》（Schmidt等人，2023，https://data.csiro.au/collection/csiro:57033）。
数据谱系：详见本数据集集合的支持文档部分，或数据文件根目录下附带的补充元数据说明。