unsaturated soil data Articles

  • Physically based closed-form expression for the bimodal unsaturated hydraulic conductivity function

    Simulation of flow and contaminant transport through the vadose zone requires accurate parameterization of the soil hydraulic properties. This requirement is particularly important for soils with a complex structure. In the present study, a physically based closed-form expression for the bimodal unsaturated hydraulic conductivity function is proposed for soils with bimodal pore-size ...


    By IWA Publishing

  • Surfactant-induced unsaturated flow: Instrumented horizontal flow experiment and hysteretic modeling

    Organic compounds with surface-active properties reduce the surface tension of water and can change soil water contact angles depending on their aqueous concentration. The presence of such compounds in the unsaturated zone affects soil moisture characteristics and unsaturated hydraulic conductivity relations, and can cause flow as a result of induced soil water pressure gradients. Some studies ...

  • Soil Fracturing

    Introduction Fracturing is an enhancement technology designed to increase the efficiency of other in situ technologies in difficult soil conditions. The fracturing extends and enlarges existing fissures and introduces new fractures, primarily in the horizontal direction. When fracturing has been completed, the formation is then subjected to vapor extraction, either by applying a vacuum to all ...

  • Soil Vapor Extraction (In Situ)

    Introduction Soil vapor extraction (SVE) is an in situ unsaturated (vadose) zone soil remediation technology in which a vacuum is applied to the soil to induce the controlled flow of air and remove volatile and some semivolatile contaminants from the soil. The gas leaving the soil may be treated to recover or destroy the contaminants, depending on local and state air discharge regulations. ...

  • Measurements of Matric Suction and Volume Changes During Inundation of Collapsible Soil

    Reduction in soil volume due to inundation under a constant total stress is a phenomenon referred to as collapse. Collapse is exhibited by soils during a change of state from an unsaturated to a saturated condition. Several researchers have postulated various theories to explain collapse behavior. Recent published research has attempted to explain the collapse phenomenon using theories of ...


    By ASTM International

  • In-Situ Anaerobic Remediation of Perchlorate-Impacted Soils

    AbstractARCADIS is currently leading the development, evaluation, and selection of a final groundwater remedy for a 94-acre manufacturing facility in the western U.S. This facility has produced small explosives and vehicular safety products since 1957. As a result of historic operations, soil and groundwater at the site have been impacted by perchlorate. To date, remediation efforts have been ...


    By Arcadis

  • Uncertainty and sensitivity analysis of water transport modelling in a layered soil profile using fuzzy set theory

    A methodology based on fuzzy set theory is presented to express imprecision of input data in a non-probabilitic sense. Imprecision may originate from indirect measurements, estimation routines, subjective interpretation, and expert judgement of available information. A numerical finite difference solution scheme was chosen to solve one-dimensional steady-state water flow in the unsaturated zone ...


    By IWA Publishing

  • In Situ Remediation of Perchlorate in Soil and Groundwater, M.S. Thesis, California State University San Bernardino

    This research project documents a technology assessment for in-situ bioremediation of perchlorate (ClO4-). The main goals are to compare methodologies, perform site characterization of soil and groundwater, and perform microcosm and bench scale tests. In this approach, perchlorate is reduced to chloride, requiring an electron donor. The suitability of electron donor amendments will be assessed ...


    By EOS Remediation, LLC

  • The importance of preferential flow in controlling groundwater recharge in tropical Africa and implications for modelling the impact of climate change on groundwater resources

    An improved water table fluctuation technique for estimating recharge is applied to a sustained (10-year) groundwater level monitoring record in Uganda, a rare dataset for tropical Africa, and compared against results from soil moisture balance models (SMBMs) and unsaturated flow models. The results show that recharge is directly proportional to rainfall (long-term average rainfall is around 1200 ...


    By IWA Publishing

  • Water dynamics and groundwater recharge in a deep vadose zone

    Understanding soil water dynamics and accurately estimating groundwater recharge are essential steps in achieving efficient and sustainable management of groundwater resources in regions with deep vadose zones. The objective of this study was to understand transient data and the dynamics nature of water from deep sections at the thick vadose zone, and to estimate groundwater recharge by ...


    By IWA Publishing

  • Electrokinetics - Technology Overview

    Electrokinetics separates and extracts contaminants from saturated or unsaturated soils, sludges and sediments, and groundwater. The goal of electrokinetic remediation is to effect the migration of subsurface contaminants in an imposed electric field via electroosmosis, electromigration and/or electrophoresis. These phenomena occur when the soil is electrically charged with a low voltage current. ...

  • Storm water infiltration in a monitored green roof for hydrologic restoration

    The objectives of this study are to provide detailed information about green roof performance in the Mediterranean climate (retained volume, peak flow reduction, runoff delay) and to identify a suitable modelling approach for describing the associated hydrologic response. Data collected during a 13-month monitoring campaign and a seasonal monitoring campaign (September–December 2008) at the green ...


    By IWA Publishing

  • Tensiometers—Theory, Construction, and Use

    Standard tensiometers are used to measure matric potential as low as -870 cm of water in the unsaturated zone by creating a saturated hydraulic link between the soil water and a pressure sensor. The direction and, in some cases, quantity of water flux can be determined using multiple installations.A variety of commercial and fabricated tensiometers are commonly used. Saturated porous ceramic ...


    By ASTM International

  • A modified Green–Ampt model for water infiltration and preferential flow

    Preferential flow is significant for its contribution to rapid response to hydrologic inputs at the soil surface and unsaturated zone flow, which is critical for flow generation in rainfall–runoff (RR) models. In combination with the diffuse and source-responsive flow equations, a new model for water infiltration that incorporates preferential flow is proposed in this paper. Its performance in ...


    By IWA Publishing

  • Water and vapor movement with condensation and evaporation in a sandy column

    The diffusion of warm, humid air into an initially cold, dry, sandy column was analyzed to study the movement of water vapor and liquid water under nonisothermal and low water content conditions. The analysis was performed using the HYDRUS-1D code. While the water retention curve of sand was measured experimentally, the unsaturated hydraulic conductivity function was inversely estimated from the ...

  • Stonehenge tunnel

    As part of proposed improvements to the A303 between Amesbury and Winterbourne Stoke in Wiltshire, the Highways Agency is planning to construct a 2.1 km long tunnel to conceal the road as it passes to the south of Stonehenge.  The tunnel will be constructed in the Chalk and the proposed tunnelling method requires dry working conditions.  In order to maintain these conditions, pumping ...

  • A forensic study to differentiate two dissolved gasoline plumes at adjoining service stations

    Three gasoline service stations are present at a highway intersection in central New Jersey. In the mid- to late- 1980s, service station “B” began to notice large discrepancies in their gasoline inventory. The USTs were removed in 1988 and a significant release was discovered. Separate-phase gasoline, as much as 1.5 feet (0.5 m) thick was present on the water table for about an area ...


    By Triassic Technology, Inc.

  • Wind-driven SVE system extracts VOCs from landfill

    An innovative soil vapor extraction (SVE) system has operated at the former Ferdula Landfill site in Frankfort, NY, for the past 10 years. The system relies on wind-driven vacuum processes rather than electrically powered air blowers to extract volatile organic compounds (VOCs) from the landfill. After a two-year trial beginning in 1998, the New York State Department of Environmental Conservation ...

  • Low-Flow (Minimal Drawdown) Ground-Water Sampling Procedures

    Untitled Document Background The Regional Superfund Ground Water Forum is a group of ground-water ...


    By Solinst Canada Ltd.

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