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Showing 1 to 18 of 18 for “"Preferential flow paths"”.
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Analysis of flow patterns and flow mechanisms in soils
Matrix flow and preferential flow can occur concurrently in the same soil. Both flow regimes produce typical flow patterns that can be visualised in dye tracer experiments. To extract quantitative information from dye tracer studies a vast variability of approaches exists. One of them is to …
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MOUNTAINHYDRO: INTEGRATING GEOLOGY, GEOPHYSICS AND HYDROGEOLOGY IN A MULTIDISCIPLINARY APPROACH
… framework for the interpretation of groundwater preferential flow paths. The geophysical pillar involves the use of high resolution DC resistivity surveys and densely spaced transient electromagnetic (EM) methods, both ground-based and airborne. Geophysical surveys play a key role in capturing …
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MONITORING INFILTRATION FROM NATURAL STORMS USING TIME-LAPSE ELECTRICAL RESISTIVITY TOMOGRAPHY
… characterization of the heterogeneity of flow through the unsaturated zone especially when compared to point measurements taken within the same survey area. The most powerful tool for understanding the unsaturated zone is a combination of several techniques. Many models of unsaturated zone …
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Geoelectric monitoring of seepage in porous media with engineering applications to earthen dams
… zones in earthen dams and determining the preferential flow paths through seepage zones in a non-invasive manner from the ground surface, 2) monitoring the transient evolution of seepage path geometry, flow velocity, and permeability in real-time if high frequency measurements can be made, …
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Identification of Recharge Source Areas in a Fractured Crystalline-rock Aquifer in Ploemeur, France
… A contact zone, which acts as the main localized flow path through the aquifer, separates the two crystalline units, and a sub-vertical permeable fault zone cross-cuts the crystalline bedrock and contact zone. Using field observations, recharge estimates, and a calibrated three-dimensional …
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Abundance, Distribution, and Geometry of Naturally Occurring Macropores in Stream Banks
Preferential flow paths are areas of substantially higher permeability than surrounding media. Macropores and soil pipes are a type of preferential flow path where conduit-like voids in the subsurface are typically greater than three millimeters in diameter. They are known to occur in agricultural …
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EVALUATION OF BEDROCK DEPTH AND SOIL INFILTRATION ALONG PENNYPACK CREEK USING ELECTRICAL RESISTIVITY TOMOGRAPHY AND MOISTURE LOGGERS
… makes predicting processes such as urban streamflow and flooding challenging. By understanding the drivers of hydraulic processes, such as soil characteristics, bedrock depth, and land use, the quality and accuracy of models can be improved. The goal of this study was to use soil moisture …
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Ground-penetrating radar images of a dye tracer test within the unsaturated zone at the Susquehanna-Shale Hills CZO
… radar (GPR) were used to image preferential flow paths in the shallow, unsaturated zone on hillslopes in two adjacent watersheds within the Susquehanna-Shale Hills Critical Zone Observatory (CZO). At each site we injected about 50 L of water mixed with brilliant blue dye (4 g/L) …
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Flow and Distribution of Water in Fractional Wettability Unsaturated Porous Media
In recent years, interest in fluid flow and transport in the unsaturated zone has gained more attention, due to growing concerns that the quality of the subsurface environment is adversely affected by agricultural, industrial, and municipal activities. The wettability properties (e.g., water …
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Development of phenomenologically-based distribution fitting procedures and spatial processes for mixed population soil properties
In the literature, two distinct flow phenomena, namely, flow through the main body of the soil, and flow through preferential flow paths, have been identified. Models which try to incorporate the effects of these two phenomena require either an explicit or an implicit knowledge of the probability …
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Electrical Resistivity Imaging of Preferenital Flow through Surface Coal Mine Valley Fills with Comparison to Other Land Forms
… imaging (ERI) to monitor subsurface hydrologic flow paths in valley fills. ERI is a non-invasive geophysical inverse technique that maps spatiotemporal changes in resistivity of the subsurface. When a resistance or conductive change is induced in the system, ERI can reveal both geologic …
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Preferential and Non-Darcy Flows in the Hyporheic Zone: Surface Water-Groundwater Hydraulics and Effects on Stream Functions
… exchange was maximized by maximizing K (flow-limited function) and thermal heterogeneity increased with K, particularly above K=10-5 m/s. Results suggest that using CFD to predict surface water-groundwater interaction may be important to accurately predict hyporheic hydraulics and …
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Preferential flow in vertically oriented, unsaturated soil layers
Preferential flow paths develop where particular areas of a geologic profile become more conductive than the surrounding material. Research has been conducted in recent years on preferential flow and the flow of water through unsaturated soils. Unfortunately, the research has been completed by …
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Microscopic study of salt precipitation dynamics during the injection process of CO2 storage in saline aquifers
… of this process, influenced by injection flow rate, pore structure, and brine properties, is crucial for optimizing CCUS strategies. This thesis examines the impact of salt precipitation on CO₂ geological storage in saline aquifers using microfluidic experiments and molecular dynamics …
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Συγκριτική αξιολόγηση μεθόδων απορρύπανσης της ακόρεστης ζώνης εδάφους μολυσμένου με κηροζίνη
… μήτρα προς μονοπάτια προτιμητέας ροής (preferential flow paths) αέρα (αερισμός). Αντιστοίχως, λόγω της χαμηλής διαπερατότητας του εδάφους, στην περίπτωση της έγχυσης ατμού ο κύριος μηχανισμός απομάκρυνσης των ημι-πτητικών και μη πτητικών συστατικών ήταν η απόσταξη ατμού (δηλαδή η μείωση …
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Characterization of legacy soil P and quantification of subsurface losses under artificial drainage
… showed that groundwater dilution from matrix flow resulted in low P concentrations within the ditch during small storm events (Q <6.4 L s–1). For large storm events (Q >6.4 L s–1), ditch water P concentrations were elevated due to high water tables interacting with high surface soil P …
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Transport and fate of veterinary sulfonamide antibiotics in soil
… mechanism in the natural soil columns can be preferential flow through macropore. A comparison of water flow and solute transport in natural and disturbed soil columns revealed that the transport processes were affected by the soil structure. The transport of the sulfonamides was typical …
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Development of risk-based groundwater operating rules: a case study of Siloam Village, South Africa
… of faults and diabase dykes which influence preferential flow paths and storage of water in the aquifer. Identified aquifer test solutions were found to be suitable for estimation of hydraulic characteristics, since they had generally good model fits and low mean residual errors. …