Gilgai microrelief DSM data of the Fitzroy catchment WA, Darwin catchments and Mitchell catchment Qld generated by the Northern Australia Water Resource Assessment

Gilgai microrelief is one of 18 attributes of soils chosen to underpin the land suitability assessment of the Northern Australia Water Resource Assessment (NAWRA) through the digital soil mapping process (DSM). Microrelief refers to variations in relief above and below the plane of the land surface due to shrink-swell clays. This gilgai microrelief raster data represents a modelled dataset of gilgai that has a vertical displacement >= 0.30m (ie that is greater than 30cm deep) and is derived from field measured site data and environmental covariates. Data values are: 1 Gilgai microrelief absent, 2 Gilgai microrelief present. Gilgai microrelief is a parameter used in land suitability assessments as severe gilgai affects machinery use, irrigation practices and can affect the establishment of irrigation infrastructure. This raster data provides improved soil information used to identify opportunities and promote detailed investigation for a range of sustainable regional development options and was created within the ‘Land Suitability’ activity of the CSIRO NAWRA. A companion dataset and statistics reflecting reliability of this data are also provided and can be found described in the lineage section of this metadata record. Processing information is supplied in ranger R scripts and attributes were modelled using a Random Forest approach.
The DSM process is described in the CSIRO NAWRA published report ‘Digital soil mapping of the Fitzroy, Darwin and Mitchell catchments. A technical report from the CSIRO Northern Australia Water Resource Assessment to the Government of Australia'. The land suitability assessment this dataset underpins is described in the CSIRO NAWRA published report ‘Land suitability of the Fitzroy, Darwin and Mitchell catchments. A technical report from the CSIRO Northern Australia Water Resource Assessment to the Government of Australia'.

吉尔盖微地形（Gilgai microrelief）是为通过数字土壤制图（Digital Soil Mapping, DSM）流程支撑北澳大利亚水资源评估（Northern Australia Water Resource Assessment, NAWRA）的土地适宜性评估而选定的18项土壤属性之一。微地形指由胀缩性黏土引发的地表平面上下的地形起伏变化。本吉尔盖微地形栅格数据为经建模得到的吉尔盖微地形数据集，其垂直位移≥0.30米（即深度大于30厘米），源于野外实测点位数据与环境协变量。数据取值规则为：1 代表无吉尔盖微地形，2 代表存在吉尔盖微地形。吉尔盖微地形是土地适宜性评估中的一项关键参数，严重的吉尔盖微地形会影响农机作业、灌溉操作，还可能干扰灌溉基础设施的搭建。本栅格数据提供了更精准的土壤信息，可用于识别发展机遇并推动针对一系列可持续区域开发方案的详细调研，其由澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation, CSIRO）NAWRA的“土地适宜性”项目研发。本数据集还附带了反映数据可靠性的配套数据集与统计信息，相关说明可参见本元数据记录的谱系章节。处理信息已通过R语言ranger脚本提供，属性建模采用了随机森林（Random Forest）方法。
数字土壤制图流程的相关说明可参见CSIRO NAWRA发布的技术报告《菲茨罗伊、达尔文与米切尔集水区数字土壤制图——澳大利亚联邦科学与工业研究组织北澳大利亚水资源评估致澳大利亚政府技术报告》。本数据集所支撑的土地适宜性评估相关说明，可参见CSIRO NAWRA发布的另一篇技术报告《菲茨罗伊、达尔文与米切尔集水区土地适宜性——澳大利亚联邦科学与工业研究组织北澳大利亚水资源评估致澳大利亚政府技术报告》。