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Artikel Jurnal
Estimating Deep Drainage Using Deep Soil Moisture Data under Young Irrigated Cropland in a Desert-Oasis Ecotone, Northwest China
Deep drainage reduces agricultural water productivity under cropland recently converted from native desert soils (i.e., young cropland) and increases the risks of nutrient and pesticide leaching into groundwater in the desert-oasis ecotone. However, the deep drainage rates under young cropland in…
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Artikel Jurnal
Mucilage Facilitates Nutrient Diffusion in the Drying Rhizosphere
Despite detailed investigations of its distinct biochemical properties and their effects on the availability of nutrients for plants, the biophysical aspects of the rhizosphere, particularly the effect of mucilage on the transport of water and nutrients, are poorly understood. The aim of this study…
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Artikel Jurnal
Modeling Internal Erosion Processes in Soil Pipes: Capturing Geometry Dynamics
The flow of water in a soil pipe and the resulting erosion of the soil pipe wall is simulated using a numerical solution of the Reynolds-averaged Navier–Stokes equations coupled with the well-known linear excess shear stress equation and the governing equation for transport of suspended sediment in…
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Artikel Jurnal
Improving the Estimation of Hydraulic and Thermal Properties of Heterogeneous Media via the Addition of Heat Loss
Heat has been widely used to investigate water flow in soils and aquifers during the past few decades. However, heat loss as an important characteristic has not been well considered in laboratory heat-tracing experiments. To evaluate the impact of heat loss on the estimation of hydraulic and…
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Artikel Jurnal
Representation of Plot-Scale Soil Heterogeneity in Dual-Domain Effective Flow and Transport Models with Mass Exchange
Agricultural soils are characterized by a structure that is strongly dependent on farming practices like tillage and trafficking. These practices can create compacted zones in the soil, thus initiating preferential flow. Two- or three-dimensional models can be used to account for the spatial…
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Artikel Jurnal
The Texas Soil Observation Network:A Comprehensive Soil Moisture Dataset for Remote Sensing and Land Surface Model Validation
The spatiotemporal variability of soil water content (SWC) at the remote sensing scale requires dense monitoring for calibration and validation. Here, we present an overview of the Texas Soil Observation Network (TxSON), an intensively monitored area in the semiarid rangelands of the central Texas…
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Artikel Jurnal
Chemically Induced Flow in Contaminated Unsaturated Soil
Laboratory experiments and numerical modeling were conducted to assess the effects of glycerol concentration gradients on water flow through an unsaturated loamy sand (Yellow bush sand, Australia) at 46% glycerol mass fraction and 12.5% volumetric water content. When the contaminated and…
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Artikel Jurnal
Field Evidence of a Natural Capillary Barrier in a Gravel Alluvial Aquifer
Ozark streams commonly feature “composite” floodplains, in which the vadose zone consists of silt or silt loam soils (∼1 m thick) overlying gravel subsoil. Previous work has shown that preferential flow paths can exist within the gravel subsoil, which can conduct water and P at rates exceeding the…
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Artikel Jurnal
Characterizing the Critical Zone Using Borehole and Surface Nuclear Magnetic Resonance
Understanding critical zone (CZ) structure below the first few meters of Earth’s surface is challenging and yet important to understand hydrologic and surface processes that influence life on Earth. Nuclear magnetic resonance (NMR) is an emerging geophysical tool that can quantify the volume of…
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Artikel Jurnal
Advanced In Situ Soil Water Sampling System for Monitoring Solute Fluxes in the Vadose Zone
To estimate potential risks of groundwater contamination, national and international environmental legislation stipulates standard values referred to pollutant contents in the soil and more rarely referred to loads in the soil leachate. Although in situ soil leachate analysis yields more realistic…
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Artikel Jurnal
Time-Dependent Sorption and Desorption of Glyphosate in Soils: Multi-reaction Modeling
The herbicide glyphosate [-(phosphonomethyl) glycine] (GPS) is commonly found offsite of application areas, despite traditional presumptions of the compound’s immobility in the environment. This suggests that further efforts to predict the behavior and fate of GPS in soils are needed. In this…
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Artikel Jurnal
Biogas Digestate Application Modifies Solute Transport Conditions in Soils and Increases the Release of Phosphorus
The application of fertilizers to soils may impair the quality of both surface and subsurface waters. Severe rainfall events that follow fertilizer application can increase P release from soils. In this study, suction plates were installed in a loamy soil with the aim of determining the P transport…
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Artikel Jurnal
Investigation of Gravity-Driven Infiltration Instabilities in Smooth and Rough Fractures Using a Pairwise-Force Smoothed Particle Hydrodynamics Model
This work investigates small-scale infiltration dynamics in smooth and rough single fractures using a three-dimensional multiphase pairwise-force smoothed particle hydrodynamics (PF-SPH) model. Gravity-driven infiltration instabilities in fractures under unsaturated conditions can significantly…
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Artikel Jurnal
An Investigation of Plume Response to Soil Vapor Extraction and Hypothetical Drum Failure
Soil vapor extraction (SVE) has been used at sites across the Department of Energy complex, including sites where legacy subsurface wastes represent a potential source of groundwater contamination. At Los Alamos National Laboratory (LANL), leakage from waste drums buried at an inactive chemical…
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Artikel Jurnal
Infiltration from the Pedon to Global Grid Scales: An Overview and Outlook for Land Surface Modeling
Infiltration in soils is a key process that partitions precipitation at the land surface into surface runoff and water that enters the soil profile. We reviewed the basic principles of water infiltration in soils and we analyzed approaches commonly used in land surface models (LSMs) to quantify…
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Artikel Jurnal
Comparing Visible–Near-Infrared Spectroscopy and a Pedotransfer Function for Predicting the Dry Region of the Soil-Water Retention Curve
The soil-water retention curve (SWRC) at the dry end, also known as soil water vapor sorption isotherms, is essential for the modeling of water vapor transport, microbial activity, and biological processes such as plant water uptake in the vadose zone. Measurement of detailed soil water vapor…
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Artikel Jurnal
Heat-Generating Nuclear Waste in Salt: Field Testing and Simulation
Investigations relating to in-drift disposal of heat-generating nuclear waste in salt have raised questions about heat–brine interactions in the unsaturated run-of-mine (RoM) salt pile used as backfill. These interactions have the potential to change the structure of the RoM salt surrounding the…
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Artikel Jurnal
Evaluating the Influence of Specimen Preparation on Saturated Hydraulic Conductivity Using Nuclear Magnetic Resonance Technology
A series of laboratory tests were performed to investigate the influences of specimen preparation on pore size distribution of soil and saturated hydraulic conductivity (). Nuclear magnetic resonance technology was used to measure the pore size distribution of the saturated samples of silty soil…
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Artikel Jurnal
Evaluating the Importance of Barometric Pumping for Subsurface Gas Transport Near an Underground Nuclear Test Site
An underground nuclear explosion (UNE) generates and distributes radioactive gases that can be transported to the ground surface though preexisting and explosion-induced fractures over timescales of hours to months. If detected, the presence of short-lived radionuclides in gas is evidence of a…