Abstract The high solubility and conservative behaviour of chloride make it ideal for use as an environmental tracer of water and salt movement through the hydrologic cycle. For such use the spatial distribution of chloride deposition in rainfall at a suitable scale must be known. A number of authors have used point data acquired from field studies of chloride deposition around Australia to construct relationships to characterise chloride deposition as a function of distance from the coast; these relationships have allowed chloride deposition to be interpolated in different regions around Australia. In this paper we took this a step further and developed a chloride deposition map for all of Australia which includes a quantification of uncertainty. A previously developed four parameter model of chloride deposition as a function of distance from the coast for Australia was used as the basis for producing a continental scale chloride deposition map. Each of the four model parameters were made spatially variable by creating parameter surfaces that were interpolated using a pilot point regularisation approach within a parameter estimation software. The observations of chloride deposition were drawn from a literature review that identified 291 point measurements of chloride deposition over a period of 80 years spread unevenly across all Australian States and Territories. A best estimate chloride deposition map was developed from the resulting surfaces on a 0.05 degree grid. The uncertainty in the chloride deposition map was quantified as the 5th and 95th percentile of 1000 calibrated models produced via Null Space Monte Carlo analysis and the spatial variability of chloride deposition across the continent was consistent with landscape morphology. The temporal variability in chloride deposition on a decadal scale was investigated in the Murray-Darling Basin, this highlighted the need for long-term monitoring of chloride deposition if the uncertainty of the continental scale map is to be reduced. Use of the derived chloride deposition map was demonstrated for a probabilistic estimation of groundwater recharge for the southeast of South Australia using the chloride mass balance method.

中文翻译：

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绘制澳大利亚氯化物沉积的空间分布图

摘要 氯化物的高溶解度和保守行为使其非常适合用作水循环中水和盐运动的环境示踪剂。对于这种用途，必须知道在适当尺度下降雨中氯化物沉积的空间分布。许多作者使用从澳大利亚周围氯化物沉积的现场研究中获得的点数据来构建关系，将氯化物沉积表征为距海岸距离的函数；这些关系允许在澳大利亚不同地区内插氯化物沉积。在本文中，我们更进一步，为整个澳大利亚开发了一张氯化物沉积图，其中包括对不确定性的量化。先前开发的氯化物沉积四参数模型作为与澳大利亚海岸距离的函数，被用作制作大陆尺度氯化物沉积图的基础。通过使用参数估计软件中的先导点正则化方法创建参数表面，使四个模型参数中的每一个在空间上可变。氯化物沉积的观察结果取自文献综述，该评论确定了 80 年间对氯化物沉积的 291 个点测量值，这些测量值在澳大利亚所有州和领地分布不均。在 0.05 度网格上从所得表面绘制出最佳估计的氯化物沉积图。氯化物沉积图中的不确定性被量化为通过零空间蒙特卡罗分析生成的 1000 个校准模型的第 5 个和第 95 个百分位数，并且整个大陆的氯化物沉积的空间变异性与景观形态一致。在墨累-达令盆地研究了十年尺度上氯化物沉积的时间变化，这突出了如果要减少大陆比例尺地图的不确定性，则需要对氯化物沉积进行长期监测。证明了使用导出的氯化物沉积图使用氯化物质量平衡方法对南澳大利亚东南部的地下水补给进行概率估计。