Soil water and fuel permeability of a Cambisol in southern Brazil and its spatial behavior: A case study

Abstract

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.

Transdisciplinary contributions and opportunities in soil physical hydrology

“…Avoiding the risk of hazardous effects on water reservoirs and human health or supporting immediate emergency decisions require knowledge on the transport behavior of these liquids in soils relative to that of water. Liu et al (1998) estimated permeability for combinations of air-oil or oil-water systems in porous media; however, results of Gonçalves-Maduro et al (2020) show that there is no simple conversion between conductivity coefficients for water, gasoline, and diesel via their dynamic viscosity and the intrinsic permeability for the clay soils investigated in this study. Moreover, conducting flow experiments on the same soil core with a sequence of these three liquids is prohibitive because gasoline and diesel affect the pore space through the development of micro-cracks.…”

“…Moreover, conducting flow experiments on the same soil core with a sequence of these three liquids is prohibitive because gasoline and diesel affect the pore space through the development of micro-cracks. Gonçalves-Maduro et al (2020) develop an approach in which the variance between parallel samples undergoing percolation experiments for different fluids separately is compared with the variance among samples with different soil texture collected at different locations in the field. The effect of soil texture on permeability is therefore distinguishable from local variability.…”

Design of soil and water conservation techniques to minimize soil erosion on degraded land in Samarinda Tenggarong Axis Road

“…Cambisol soil results in flandform weathering of parent rocks and has a low organic matter content. Basedon after assessing the proportions of sand, clay, and silt, the cambisol's texture that was examined was categorized as clay-rich [15]. Podzolic soils are a type of soil formed by high rainfall and are also a type of old mineral soil.…”

Fuzzy Modelling to Describe the Pollutant Concentration in Fluids

“…Analyzing soil contamination, when soil columns with solutes are assessed in the laboratory, the infiltration rate or Darcy's velocity [7,10] is applied because of the uncertainty in the convective flow of the solution water+pollutant. The capillary and larger soil pores are not perfect pipes, ranging their geometry in space and time and, therefore, result in velocity uncertainty.…”

“…Thus, our formulation may also be applied to practical unidimensional circunstances of fluids transport, in which the wet front with effluent concentration moves towards in the x direction (for all y and z constants). This case supposes that the transport is high and given by the Darcy's law [7,10] when the pressure gradient is known and the capillary diffusion neglected in the other directions. It is also possible to applied it in two-dimensional problems (x, z), where the concentration varies only in the x direction and the pollutant quickly reaches the water table, observing its displacement in the x direction by pressure gradients of Darcy.…”