This paper presents a numerical model based on the Lattice Boltzmann Method (LBM), developed for studying dynamic responses of an unsaturated porous medium to periodic imbibition and drainage induced by a cyclic water table movement. The model includes gravity which helps defining an hydraulic head. The model predicted an incremental increase of the overall water content in the medium over each...

Hydrological modeling of the unsaturated soil zone fluxes allows the transfer processes simulation through the hydrological active soil zone. The pedotransfer functions (FTP) are useful tools in the modeling process. They contain analytical functions derived through statistic optimization process using a large amount of soil information data. This paper aims to analyze the level of reliability ...

A substantial reservoir (up to 1 kg ha(-1)) of natural perchlorate is present in diverse unsaturated zones of the arid and semi-arid southwestern United States. The perchlorate co-occurs with meteoric chloride that has accumulated in these soils throughout the Holocene [0 to 10-15 ka (thousand years ago)] and possibly longer periods. Previously, natural perchlorate widely believed to be limited...

This paper presents a study for solving unsaturated flow in heterogeneous porous media using the meshless method with radial basis function (RBF). For modeling nonlinear hydrological process zone, an exponential model is introduced Richards equation such that we may obtain linearized equation. We adopt multiquadric as RBF simulating problems layered soils, flux and head must satisfy continuity ...

In this study we develop a first-order, nonstationary stochastic model for steady state, unsaturated flow in randomly heterogeneous media. The model is applicable to the entire domain of a bounded vadose zone, unlike most of the existing stochastic models. Because of its nonstationarity, we solve it by the numerical technique of finite differences, which renders the flexibility in handling diff...

Unsaturated soil is a form of natural whose pores are filled by air and water. Different from saturated soil, the microstructure unsaturated consists three phases, namely, solid phase (soil particle), vapor phase, liquid phase. Due to matric suction pores, hydraulic mechanical behaviors soils present significant dependence on moisture condition, which usually results in series unpredictable ris...

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In accordance with the migration and transformation laws of pollutants in soil groundwater, research progress chemical fertilizers, pesticides, sewage irrigation is reviewed systematically from three perspectives: topsoil layer, underground aquifer, unsaturated zone. The results study various water layers soils illuminate current research's problems future directions.

salinization is the main characteristic of soils in arid and semi-arid regions which reduce the agricultural potential ofirrigated lands. therefore, soil reclamation as well as determination of the leaching requirement for salt control is veryimportant for better plant growth. in this study, the effects of leaching on saline soils of sistan region, southeast of iranwere examined using unsaturat...

contaminant transport and degradation in soils have represented biodegradation as a first-order decay proAn experimental and numerical investigation was conducted to cess, without actually considering microbial processes and study interactions between microbial dynamics and transport processes in variably saturated porous media. Experiments were contheir interactions with other transport proces...