New South Wales – Dryland Salinity Assessment 2000 – Assessmet of Dryland salinity extent 2050

\r\n\r\nThe data shows areas of dryland salinity risk in 2050 in the Murray-Darling\r\nBasin.Areas of risk are based on groundwater levels and air photo\r\ninterpretation. The merged data, at a nominal scale of 1:250 000, show actual\r\nareas where dryland salinity or water-tables less than 2 metres have been\r\nmeasured. For the extent map, every delineated area is underpinned by either\r\nair photo data or by one or more groundwater bores. Therefore, the area at\r\nrisk is regarded as conservative due to limitations in the spatial coverage of\r\nair photo and bore data. number of techniques to spatially extrapolate these\r\ndata to infer potential areas at risk were trialed but were considered\r\nscientifically or statistically inadequate. Estimates of impacts are based on\r\nareas at risk having groundwater levels of less than 2 m. An impact assessment\r\nbased on groundwater less than 5 m and rising was considered inappropriate.\r\nTotal areas affected with groundwater less than 5 m and rising have been\r\npresented, but only for improved consistency with other States.\r\n\r\nSee [further metadata](http://data.daff.gov.au/anrdl/metadata_files/pa_dsa__r1in\r\n__00111a03.xml) for more detail.\r\n\r\n

本数据集展示了墨累-达令盆地（Murray-Darling Basin）2050年的旱地盐渍化（dryland salinity）风险区域。风险区域的判定依据为地下水位与航空相片解译结果。合并后的数据标称比例尺为1:250 000，标注了已实测存在旱地盐渍化或地下水位埋深小于2米的实际区域。对于该范围地图，每一处划定的区域均有航空相片数据或一口及以上地下水钻孔数据作为支撑。鉴于航空相片与钻孔数据的空间覆盖存在局限，本数据集所呈现的风险区域被认为是保守估算值。

曾尝试多种空间外推技术以推断潜在风险区域，但这些技术均被认为在科学或统计层面存在不足。

影响评估基于地下水位埋深小于2米的风险区域开展。而基于地下水位埋深小于5米且水位呈上升趋势的影响评估则被认为并不恰当。为与其他州的数据集保持更高一致性，本次也公布了地下水位埋深小于5米且水位呈上升趋势的受影响总面积。

详细信息请参阅[补充元数据](http://data.daff.gov.au/anrdl/metadata_files/pa_dsa__r1in__00111a03.xml)。