Great Artesian Basin - Cadna-owie Hooray Aquifer - Sulphate Concentration

Data used to produce the predicted Sulphate map for the Cadna-owie - Hooray Aquifer in the Hydrogeological Atlas of the Great Artesian Basin (Ransley et.al., 2015).There are four layers in the Cadna-owie - Hooray Aquifer Sulphate map dataA. Location of hydrochemistry samples (Point data, Shapefile)B. Predicted Concentration (Filled contours , Shapefile)C. Predicted Concentration Contours (Contours, Shapefile)D. Prediction Standard Error (Filled contours , Shapefile)The predicted values provide a regional based estimate and may be associated with considerable error. It is recommended that the predicted values are read together with the predicted error map, which provides an estimate of the absolute standard error associated with the predicted values at any point within the map.The predicted standard error map provides an absolute standard error associated with the predicted values at any point within the map. Please note this is not a relative error map and the concentration of a parameter needs to be considered when interpreting the map. Predicted standard error values are low where the concentration is low and there is a high density of samples. Predicted standard errors values can be high where the concentration is high and there is moderate variability between nearby samples or where there is a paucity of data.Concentrations are Sulphate in mg/L.Coordinate system is Lambert conformal conic GDA 1994, with central meridian 134 degrees longitude, standard parallels at -18 and -36 degrees latitude.The Cadna-owie - Hooray Aquifer Sulphate map is one of 14 hydrochemistry maps for the Cadna-owie - Hooray Aquifer and 24 hydrochemistry maps in the Hydrogeological Atlas of the Great Artesian Basin (Ransley et.al., 2014). This dataset and associated metadata can be obtained from www.ga.gov.au, using catalogue number 81697. References:Hitchon, B. and Brulotte, M. (1994): Culling criteria for 'standard' formation water analyses; Applied Geochemistry, v. 9, p. 637-645Ransley, T., Radke, B., Feitz, A., Kellett, J., Owens, R., Bell, J. and Stewart, G., 2015. Hydrogeological Atlas of the Great Artesian Basin. Geoscience Australia. Canberra. [available from www.ga.gov.au using catalogue number 79790]

本数据集用于制作《大自流盆地水文地质图集（Hydrogeological Atlas of the Great Artesian Basin）》（Ransley等人，2015）中Cadna-owie-Hooray含水层的硫酸盐（Sulphate）预测分布图。
Cadna-owie-Hooray含水层硫酸盐分布图数据集包含4个图层：
A. 水文地球化学采样点位数据（点数据，形状文件（Shapefile））
B. 预测浓度（等值线填充图，形状文件（Shapefile））
C. 预测浓度等值线（矢量等值线，形状文件（Shapefile））
D. 预测标准误差（等值线填充图，形状文件（Shapefile））

该预测值仅提供区域尺度的估算结果，可能伴随显著误差。建议结合预测误差分布图一同解读预测值——该误差分布图可估算地图范围内任意点位的预测值所对应的绝对标准误差。

预测标准误差分布图可给出地图范围内任意点位的预测值所对应的绝对标准误差。请注意，本数据并非相对误差图，解读时需结合对应参数的浓度水平。当浓度较低且采样点密度较高时，预测标准误差值较低；而当浓度较高、邻近采样点间变异程度中等，或数据匮乏时，预测标准误差值通常较高。

浓度项为硫酸盐（Sulphate），单位为毫克每升（mg/L）。

坐标系采用兰伯特共形圆锥投影（Lambert conformal conic）GDA 1994，中央经线为东经134°，标准纬线为南纬18°与南纬36°。

Cadna-owie-Hooray含水层硫酸盐分布图是该含水层14张水文地球化学图件之一，同时也是《大自流盆地水文地质图集》（Ransley等人，2014）中的24张水文地球化学图件之一。本数据集及相关元数据可通过澳大利亚地球科学局官网（www.ga.gov.au）获取，目录编号为81697。

参考文献：
1. Hitchon, B. 与 Brulotte, M. (1994)：《“标准”地层水分析的筛选标准》，《应用地球化学（Applied Geochemistry）》，第9卷，第637-645页
2. Ransley, T.、Radke, B.、Feitz, A.、Kellett, J.、Owens, R.、Bell, J. 与 Stewart, G., 2015：《大自流盆地水文地质图集（Hydrogeological Atlas of the Great Artesian Basin）》，澳大利亚地球科学局（Geoscience Australia），堪培拉。[可通过www.ga.gov.au获取，目录编号79790]