The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Ali A Ameli - One of the best experts on this subject based on the ideXlab platform.
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the Exponential Decline in saturated hydraulic conductivity with depth a novel method for exploring its effect on water flow paths and transit time distribution
Hydrological Processes, 2016Co-Authors: Ali A Ameli, Kevin Bishop, Jeffrey J McdonnellAbstract:The strong vertical gradient in soil and subsoil saturated hydraulic conductivity is characteristic feature of the hydrology of catchments. Despite the potential importance of these strong gradients, they have proven difficult to model using robust physically based schemes. This has hampered the testing of hypotheses about the implications of such vertical gradients for subsurface flow paths, residence times and transit time distribution. Here we present a general semi-analytical solution for the simulation of 2D steady-state saturated-unsaturated flow in hillslopes with saturated hydraulic conductivity that Declines Exponentially with depth. The grid-free solution satisfies mass balance exactly over the entire saturated and unsaturated zones. The new method provides continuous solutions for head, flow and velocity in both saturated and unsaturated zones without any interpolation process as is common in discrete numerical schemes. This solution efficiently generates flow pathlines and transit time distributions in hillslopes with the assumption of depth-varying saturated hydraulic conductivity. The model outputs reveal the pronounced effect that changing the strength of the Exponential Decline in saturated hydraulic conductivity has on the flow pathlines, residence time and transit time distribution. This new steady-state model may be useful to others for posing hypotheses about how different depth functions for hydraulic conductivity influence catchment hydrological response. Copyright © 2016 John Wiley & Sons, Ltd.
Kevin Bishop - One of the best experts on this subject based on the ideXlab platform.
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the Exponential Decline in saturated hydraulic conductivity with depth a novel method for exploring its effect on water flow paths and transit time distribution
Hydrological Processes, 2016Co-Authors: Ali A Ameli, Kevin Bishop, Jeffrey J McdonnellAbstract:The strong vertical gradient in soil and subsoil saturated hydraulic conductivity is characteristic feature of the hydrology of catchments. Despite the potential importance of these strong gradients, they have proven difficult to model using robust physically based schemes. This has hampered the testing of hypotheses about the implications of such vertical gradients for subsurface flow paths, residence times and transit time distribution. Here we present a general semi-analytical solution for the simulation of 2D steady-state saturated-unsaturated flow in hillslopes with saturated hydraulic conductivity that Declines Exponentially with depth. The grid-free solution satisfies mass balance exactly over the entire saturated and unsaturated zones. The new method provides continuous solutions for head, flow and velocity in both saturated and unsaturated zones without any interpolation process as is common in discrete numerical schemes. This solution efficiently generates flow pathlines and transit time distributions in hillslopes with the assumption of depth-varying saturated hydraulic conductivity. The model outputs reveal the pronounced effect that changing the strength of the Exponential Decline in saturated hydraulic conductivity has on the flow pathlines, residence time and transit time distribution. This new steady-state model may be useful to others for posing hypotheses about how different depth functions for hydraulic conductivity influence catchment hydrological response. Copyright © 2016 John Wiley & Sons, Ltd.
Jeffrey J Mcdonnell - One of the best experts on this subject based on the ideXlab platform.
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the Exponential Decline in saturated hydraulic conductivity with depth a novel method for exploring its effect on water flow paths and transit time distribution
Hydrological Processes, 2016Co-Authors: Ali A Ameli, Kevin Bishop, Jeffrey J McdonnellAbstract:The strong vertical gradient in soil and subsoil saturated hydraulic conductivity is characteristic feature of the hydrology of catchments. Despite the potential importance of these strong gradients, they have proven difficult to model using robust physically based schemes. This has hampered the testing of hypotheses about the implications of such vertical gradients for subsurface flow paths, residence times and transit time distribution. Here we present a general semi-analytical solution for the simulation of 2D steady-state saturated-unsaturated flow in hillslopes with saturated hydraulic conductivity that Declines Exponentially with depth. The grid-free solution satisfies mass balance exactly over the entire saturated and unsaturated zones. The new method provides continuous solutions for head, flow and velocity in both saturated and unsaturated zones without any interpolation process as is common in discrete numerical schemes. This solution efficiently generates flow pathlines and transit time distributions in hillslopes with the assumption of depth-varying saturated hydraulic conductivity. The model outputs reveal the pronounced effect that changing the strength of the Exponential Decline in saturated hydraulic conductivity has on the flow pathlines, residence time and transit time distribution. This new steady-state model may be useful to others for posing hypotheses about how different depth functions for hydraulic conductivity influence catchment hydrological response. Copyright © 2016 John Wiley & Sons, Ltd.
P A Mcdaniel - One of the best experts on this subject based on the ideXlab platform.
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a hillslope scale experiment to measure lateral saturated hydraulic conductivity
Water Resources Research, 2004Co-Authors: Erin S Brooks, Jan Boll, P A McdanielAbstract:[1] One of the most challenging parameters in hillslope- and watershed-scale, distributed, hydrologic models is the lateral saturated hydraulic conductivity (Ks). In this paper, we present a methodology to determine the hillslope-scale lateral Ks above a moderately deep sloping restrictive layer in an 18 × 35 m hillslope plot using perched water level measurements and drain tile outflow data. The hillslope-scale lateral Ks was compared to small-scale Ks measured with small soil cores and the Guelph permeameter. Our results show that small-scale Ks measurements underestimate the actual hillslope-scale Ks. The hillslope-scale Ks measurements were 13.7, 4.1, and 3.2 larger than small soil core measurements in the A, B, and E horizons, respectively. We argue that the gap between small-scale and hillslope-scale Ks within the same porous medium is foremost a measurement problem. Data analysis provided the Ks distribution with depth, showing a sharp decrease in Ks within the first 0.1 m of the soil and an Exponential Decline in Ks below 0.1 m. The distribution of Ks with depth was best described by a double-Exponential relationship. Overall, results indicate the importance of macroporosity, perhaps of biological origin, in determining Ks at a hillslope scale.
Erin S Brooks - One of the best experts on this subject based on the ideXlab platform.
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a hillslope scale experiment to measure lateral saturated hydraulic conductivity
Water Resources Research, 2004Co-Authors: Erin S Brooks, Jan Boll, P A McdanielAbstract:[1] One of the most challenging parameters in hillslope- and watershed-scale, distributed, hydrologic models is the lateral saturated hydraulic conductivity (Ks). In this paper, we present a methodology to determine the hillslope-scale lateral Ks above a moderately deep sloping restrictive layer in an 18 × 35 m hillslope plot using perched water level measurements and drain tile outflow data. The hillslope-scale lateral Ks was compared to small-scale Ks measured with small soil cores and the Guelph permeameter. Our results show that small-scale Ks measurements underestimate the actual hillslope-scale Ks. The hillslope-scale Ks measurements were 13.7, 4.1, and 3.2 larger than small soil core measurements in the A, B, and E horizons, respectively. We argue that the gap between small-scale and hillslope-scale Ks within the same porous medium is foremost a measurement problem. Data analysis provided the Ks distribution with depth, showing a sharp decrease in Ks within the first 0.1 m of the soil and an Exponential Decline in Ks below 0.1 m. The distribution of Ks with depth was best described by a double-Exponential relationship. Overall, results indicate the importance of macroporosity, perhaps of biological origin, in determining Ks at a hillslope scale.
