Thermal enhancement of natural magnetism as a tool for tracing eroded soil
Thermal enhancement of natural magnetism as a tool for tracing eroded soil
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DOI：
10.1002/esp.3312
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发表时间：
2012-11
影响因子：
3.3
通讯作者：
A. Armstrong;J. Quinton;B. Maher
中科院分区：
文献类型：
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作者：
A. Armstrong;J. Quinton;B. Maher
考虑到侵蚀土壤的来源、数量和移动距离对场地内外的影响，以及与沉积物相关的养分、金属和微生物的运输，以及为土壤侵蚀模型的开发和验证提供数据的持续需求，确定侵蚀土壤的来源、数量和移动距离变得越来越重要。许多土壤示踪剂已经开发出来；然而，大多数都含有外来物质，如荧光珠和稀土氧化物，由于它们的物理特性不同，因此对示踪结果的有效性产生了怀疑。为了避免这些问题，我们研究了在还原条件下加热土壤以提高其铁磁性含量作为土壤侵蚀示踪剂的潜力；虽然这项技术已经成功地用于追踪河流沉积物，但尚未成功地应用于土壤侵蚀研究。对于一组16个磁浓度相关的性质，发现加热后的值明显更大，至少一个数量级，无论是散装土壤还是9个单独的粒度分数。可以使用两种不同的磁性来区分单个粒度的组分，从而说明该技术在提供粒度特定侵蚀信息方面的潜力。土壤箱试验表明，在现场测量磁化率和实验室测量侵蚀沉积物的磁性，以追踪和量化土壤侵蚀的潜力。因此，具有人工增强铁磁特性的加热土壤被成功地证明具有作为特定尺寸、成本效益和代表性土壤侵蚀示踪剂的巨大潜力。版权所有©2012 John Wiley & Sons， Ltd。
Determining sources, quantities and travel distances of eroding soil is of increasing importance given its impact on‐ and off‐site, the sediment‐associated transport of nutrients, metals and micro‐organisms and the ongoing need to provide data for soil erosion model development and validation. Many soil tracers have been developed; however, most comprise foreign materials, such as fluorescent beads and rare earth oxides, which cast doubts on the validity of tracing results given their different physical characteristics. To avoid these problems, we have investigated the potential of soil, which has been heated under reducing conditions to enhance its ferrimagnetic content, as a soil erosion tracer; while the technique has been used successfully to trace river sediment it has not been successfully applied to soil erosion studies. For a suite of 16 magnetic concentration‐dependent properties, values were found to be significantly greater, by at least one order of magnitude, after heating, both for the bulk soil and nine individual particle size fractions. Individual size fractions could be differentiated using two different magnetic properties, thus illustrating the technique's potential to provide information on particle size‐specific erosion. Soil box experiments demonstrated the potential for both in situ measurement of magnetic susceptibility and laboratory measurement of the magnetic properties of eroded sediment, to trace and quantify soil erosion. Thus, heated soil, with artificially‐enhanced ferrimagnetic properties, is successfully demonstrated to have great potential as a size‐specific, cost‐effective and representative soil erosion tracer. Copyright © 2012 John Wiley & Sons, Ltd.