The high demand for fuel derived from oil increases the risk of environmental hazard in agricultural fields caused by accidents with the operation of machines and spotting of fuel on the ground. When these accidents occur, a part of the spilled fuel infiltrates and redistributes in the soil according to the fuel's own physical properties. Most fuel products are light nonaqueous‐phase liquids (NAPL) and contain compounds that are toxic and cause damage to the soil and to human health. The transport behavior of fuels in soils has been extensively studied but is lacking knowledge in specific soils with high clay content. This study aimed to evaluate the soil permeability (K) to the transport of water and fuels and their spatial variation in a Cambisol in southern Brazil. Furthermore, the question should be addressed whether K_water may be used to estimate K_fuels based on the fluid viscosities. Moreover, a spatial variance analysis should evaluate the variability between replicate repacked samples at a particular location in comparison with spatial variability caused by soil texture and bulk density differences. Results showed that K_water was, on average, 4.5 times smaller than K_gasoline and 1.25 times smaller than K_diesel, that the correlation between measured and estimated K_fuels was moderately positive for the clayey soil investigated, and that a minimum set of three repacked parallel cores for each sampling location yields a local variance that is much smaller than the semivariance at any lag distance.

中文翻译：

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巴西南部坎比索尔土壤水和燃料的渗透性及其空间行为：一个案例研究

对来自石油的燃料的高需求增加了由于机器操作和地面上的燃料点滴事故而在农业领域造成环境危害的风险。当这些事故发生时，一部分泄漏的燃料会根据燃料自身的物理特性渗入土壤并重新分布在土壤中。大多数燃料产品是轻质非水相液体（NAPL），并且包含有毒化合物，会对土壤和人类健康造成损害。燃料在土壤中的运输行为已被广泛研究，但在粘土含量高的特定土壤中缺乏知识。这项研究旨在评估土壤渗透率（K）用于巴西南部坎比索尔的水和燃料运输及其空间变化。此外，应解决以下问题：是否可以使用K_水根据流体粘度估算K_燃料。此外，与由土壤质地和堆积密度差异引起的空间变异性相比，空间变异性分析应该评估在特定位置的重复装填样品之间的变异性。结果表明，ķ_水是，平均来说，小于4.5倍ķ_汽油和小于1.25倍ķ_柴油，即测量和估计之间的相关性ķ_燃料 对所研究的粘土土壤呈中等正值，并且对于每个采样位置，最少包含三个重新包装的平行岩心的集合产生的局部方差比在任何滞后距离处的半方差小得多。