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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"macropore flow"”.
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AN INVESTIGATION OF SOIL WATER MOVEMENT ON DRAINED AND UNDRAINED CLAY GRASSLAND IN SOUTH WEST ENGLAND
… runoff ( ~ 400 mm) but did change the dominant flowpaths. Drainage diverted water from surface/near surface routes to depth so that drain storm runoff was lagged by some 30 minutes over undrained site discharge. The drained site also exhibited a more peaky regime, with a maximum daily discharge …
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Evaluation of flow models and pollutant retention isotherms for their application to rain garden bioretention
… affecting their retention were found to be macropore flow, pore water velocity, soil moisture content and soil characteristics and the primary method of modelling capture was identified as a sorption isotherm. Thus a dual-permeability heavy metal sorption model was developed; this was based …
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Integrated Numerical Modeling of Spatial and Time-Variant Hydrologic Response in Subsurface Drained Watersheds
… simulate post-rainfall event recessions. Drain flow simulations that included macropore flow resulted in higher magnitudes of response and better agreement with observed data, compared to simulations that considered sorptive flow alone. Simulations also showed that drain responses were in better …
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Impacts of biota on bioretention cell function during establishment in the Midwest
… in improving water quality, indicating that macropore flow in the earthworm treatments did not induce a higher rate of pollutant transport.
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Modification and Evaluation of a Water Balance Model to Simulate Corn Yields in Drained Waterways
… to include a variable hydraulic gradient and a macropore flow component.<br /> The water balance model was run for 17 years of climatic data (1986-1989, 1992-2000, and 2002-2005) collected at Brookings, South Dakota. The simulations were run for two conditions, one condition containing …
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The Influence of Trees on Soil Hydraulic Properties : Species Effects and the Provision of Ecosystem Services.
… effect of trees on Ks. An investigation of soil flow pathways and pore characteristics showed that significantly higher Ks corresponded with significantly higher soil macroporosity and macropore flow. A mesocosm experiment, undertaken to investigate the influence of tree roots and associated soil …
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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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Effect of urinary nitrogen, dairy shed effluent and nitrogen fertiliser on nitrate leaching from a pasture soil
… the two year lysimeter experiment. The role of macropore flow on nitrate-N leaching was determined in a second lysimeter experiment. The results from the two year experiment were also used to test the accuracy and the utility of the LEACHN model to predict nitrate-N leaching losses. In the two …
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Impact of Isotopic Heterogeneity in Shallow Systems on Modeling of Stormflow Generation
… in hydrologic and geochemical modeling of stormflow generation in watersheds has been quantification of the contributions of water and solutes from different sources and hydrologic pathways to streamwater. Isotopic techniques have recently gained widespread acceptance as useful tools in the …
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Measurement and Simulation of Preferential Flow in Frozen Soils
… functioning of cold regions. Preferential flow in macropores may enhance infiltration into frozen soil, but flow dynamics are complicated by coupled water and heat transfer processes. Field studies were conducted in the Canadian Prairies to evaluate the dominant mechanisms controlling …
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Investigation of hydrologic and sediment transport processes on riparian hillslopes
… of riparian slopes that can be used to quantify flow concentration on hillslopes. The riparian hillslope model was used to investigate the dynamics of hydrologic and sediment transport processes. Field investigations revealed that riparian hillslopes were dissected into distinct convergent, …
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THE EFFECTS OF WHOLE TREE HARVESTING ON SITE HYDROLOGY AND SOIL STRUCTURE AT BEDDGELERT FOREST, N. WALES, UK
… a soil with high conductivity. However, frequent macropore flow was not observed at the site. Tensiometer results showed that the mineral soil remained unsaturated. Therefore, a type of preferential flow dominates at both sites. A one dimensional modelling approach to soil water movement confirmed …
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INVESTIGATIONS OF PREFERENTIAL AND MATRIX FLOW IN A MOLE DRAINED SOIL BLOCK
… North Wyke, Devon, to investigate preferential flow through a poorly structured relatively impermeable soil. Macropore channels were added by a mole plough in order to investigate soil water pathways and chemical transport in a soil in which preferential flow was guaranteed. The investigation …
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Preferential movement of solutes through soils
… soils. This research focuses on preferential flow and solute transport processes and the effects of agricultural management practices on these processes. Experimental methods for monitoring preferential flow and solute transport in the field as well as a stochastic, physically-based model for …
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Dissolved organic carbon and colour dynamics in drained and restored blanket peat
… saturation and the occurrence of overland flow (OLF), resulting in a greater volume of water being drawn down into the peat body. The reduced saturation levels caused the subsidence and compaction of the upper soil layers, which increased the bulk density and ultimately reduced the degree …
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Flow and transport processes as affected by tillage management under monsoonal conditions in South Korea
… under monsoonal conditions and its impact on flow processes and nitrate transport was investigated. On hillslopes, we monitored surface and subsurface flow processes in four plastic mulched potato fields using a network of tensiometers, FDR sensors, runoff collectors and flow dividers as well …