نتایج جستجو برای: soil permeability
تعداد نتایج: 229695 فیلتر نتایج به سال:
In this paper we discuss the numerical modelling of two inverse problems in porous media flow. In the first problem, we determine the soil parameters that occur in the retention and hydraulic permeability curves of the Van Genuchten ansatz for Richard’s equation. In the second problem we determine the hydraulic permeability, longitudinal dispersivity and adsorption isotherms using the measureme...
Minimizing atmospheric emissions of soil fumigants is critical for protecting human and environmental health. Covering the soil surface with a plastic tarp is a common approach to restrict fumigant emissions. The mass transfer of the fumigant vapors through the tarp is often the rate-limiting factor in fumigant emissions. An approach for standardizing measurements of film permeability is propos...
This study investigates the feasibility of management of aquifer recharge (MAR) in Lebanon by designing well barriers to remove seawater intrusion from the fractured carbonate aquifers. Groundwater flow and saltwater/freshwater 50% sharp interface have been modeled along the coastal area using the Ghyben-Herzberg theory. The groundwater flow simulations have been supported by field transmissivi...
Soil fumigation in greenhouses or agricultural fields often includes tarping the soil surface with polyethylene (PE) films to contain the fumigant in the soil and reduce emissions to the atmosphere. Previous research has demonstrated that PE films are permeable to methyl bromide and other fumigant compounds. In these experiments, the effect of temperature, fumigant mixtures, condensed water, an...
Intercomparisons of hillslopes and catchments in different hydrogeomorphic settings are rare. Those comparison studies that have been completed have focused largely on bulk outflow and chemistry. Here, we present a new functional intercomparison of two well studied hillslopes: one in New Zealand at Maimai and one in Japan at Fudoji. Slope angle, slope length, soil depth, climate and vegetation ...
A system of preventive protection of houses against radon penetration from the ground [1] has been in operation for more than 15 years in the Czech Republic. The determination of a so-called radon index of the building site represents the first step. The assessment is based on measurements of soil gas radon concentration and on the determination of soil permeability. During the years, the metho...
This paper presents the laboratory test results of vertical infiltration on two soil columns of finer over coarser soils subject to simulated rainfalls under conditions of no-ponding at the surface and constant head at the bottom. The main objectives were to evaluate the effect of rainfall intensity and duration; and to provide experimental evidence for soil water redistribution and hysteresis....
[1] The role of upslope soil pore water pressure on lateral subsurface storm flow dynamics is poorly understood. Further development of hillslope hydrologic models requires new understanding from field understanding. In particular, we need new, quantifiable measures that link upslope soil pore pressure and water table dynamics to the timing and volume of subsurface storm flow. Here we examine t...
Barometric pressure changes can induce airflow in an open borehole or well screened in the vadose zone, thereby ventilating the soil surrounding the borehole. This paper presents an analytic model of the induced airflow and compares the predictions of the model with experimental measurements. This model may be useful for the design of passive soil vapor extraction as applied to the remediation ...
Degradation of plant patches is considered as one of the indices for rangeland degrading health condition. Investigating the accuracy of triple indices (infiltration, stability and soil nutrient cycle) presented by LFA method seems necessary to determine its efficiency in semi-arid areas with the least cost. This study aims to investigate the role of vegetative species and growing forms on soil...
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