Academic literature on the topic 'Hydraulic flow zone'
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Journal articles on the topic "Hydraulic flow zone"
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Beal, Cara D., Ted Gardner, David W. Rassam, Alison M. Vieritz, and Neal W. Menzies. "Effluent flux prediction in variably saturated soil zones within a septic tank—soil absorption trench." Soil Research 44, no. 7 (2006): 677. http://dx.doi.org/10.1071/sr06007.
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The treatment and hydraulic mechanisms in a septic tank–soil absorption system (SAS) are highly influenced by the clogging layer or biomat zone which develops on bottom and lower sidewall surfaces within the trench. Flow rates through the biomat and sub-biomat zones are governed largely by the biomat hydraulic properties (resistance and hydraulic conductivity) and the unsaturated hydraulic conductivity of the underlying soil. One- and 2-dimensional models were used to investigate the relative importance of sidewall and vertical flow rates and pathways in SAS. Results of 1-dimensional modelling show that several orders of magnitude variation in saturated hydraulic conductivity (Ks) reduce to a 1 order of magnitude variation in long-term flow rates. To increase the reliability of prediction of septic trench hydrology, HYDRUS-2D was used to model 2-dimensional flow. In the permeable soils, under high trench loading, effluent preferentially flowed in the upper region of the trench where no resistant biomat was present (the exfiltration zone). By comparison, flow was more evenly partitioned between the biomat zones and the exfiltration zones of the low permeability soil. An increase in effluent infiltration corresponded with a greater availability of exfiltration zone, rather than a lower resistance of biomat. Results of modelling simulations demonstrated the important role that a permeable A horizon may play in limiting surface surcharge of effluent under high trench hydraulic loading.
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Tannant, D. D., P. K. Kaiser, and D. H. Chan. "Effect of tunnel excavation on transmissivity distributions and flow in a fracture zone." Canadian Geotechnical Journal 30, no. 1 (February 1, 1993): 155–69. http://dx.doi.org/10.1139/t93-014.
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During an excavation-response experiment performed at the Underground Research Laboratory (Atomic Energy of Canada Limited, Pinawa, Man.) a decrease in fracture-zone transmissivity was measured as a tunnel intersected the room 209 fracture zone. The decrease in transmissivity was greatest as the pilot and the slash faces passed the fracture zone. The transmissivities increased towards their preexcavation values as the faces proceeded past the fracture zone. This response suggested that shear stresses or displacements controlled the hydraulic behaviour of the fractures. The hydraulic response in the fracture zone was analyzed using finite element models. Predictions of shear-displacement distributions in the fracture zone as a function of face position were obtained from a three-dimensional finite element model using joint elements to represent the fracture zone. A phenomenological relationship between shear displacement and transmissivity change was used to modify the transmissivity distributions in the fracture zone based on shear displacements for different excavation stages. Seepage analyses with these transmissivities provided predictions that matched closely the field measurements obtained from the room 209 fracture zone. These results and the inability of conventional, normal stress dependent, fracture closure to predict consistently the hydraulic response support the concept of shear causing a reduction in fracture-zone transmissivity. Excavation-dependent, shear-induced reduction in transmissivity provides an alternate mechanism for interpreting and understanding the hydraulic response of disturbed fracture zones. Key words : transmissivity, shear displacement, fluid flow, fracture zone, excavation.
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Tannant, D. D., and P. K. Kaiser. "A shear-dependent fracture-zone transmissivity model." Canadian Geotechnical Journal 30, no. 1 (February 1, 1993): 146–54. http://dx.doi.org/10.1139/t93-013.
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Shear displacements caused by excavation through a fracture zone can decrease the overall fracture-zone transmissivity. The complex arrangement of flow channels found in fracture zones creates a situation where imposed shear displacements will reduce the aperture of critically oriented fractures. This paper presents a simple flow model based on the en echelon structure found in many fracture zones from which a phenomenological relationship between shear displacement and transmissivity change is established. This model is then used to demonstrate the effect of shear displacement around a circular opening. The effects of shear-induced decreases in transmissivity are most dramatic when a continuous low-transmissivity zone is created around the opening. In this case, the steady-state heads can be relatively high and the resulting hydraulic gradient into the excavation can be extremely large. If the low-transmissivity zone around the opening is discontinuous because, for example, the shear displacements are nonaxisymmetric, then the inflow becomes channelled and the steady-state heads and hydraulic gradients near the excavation substantially decrease. The concept of shear-induced transmissivity reduction in fracture zones provides an alternative mechanism to shear-induced dilation and normal stress induced fracture closure for interpreting and explaining the observed hydraulic response in fracture zones. Key words : transmissivity, shear displacement, fluid flow, en echelon fractures, fracture zone, excavation.
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Pozdniakov, S. P., N. E. Sizov, and V. A. Lekhov. "THE SIZE OF THE SANITARY PROTECTION ZONE OF THE WATER INTAKE WELL IN THE LAYERED HETEROGENEOUS AQUIFER." Engineering Geology World 14, no. 2 (September 3, 2019): 74–81. http://dx.doi.org/10.25296/1993-5056-2019-14-2-74-81.
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Sanitary protection zones (SPZ) of water intakes allocate on the time of movement from the outer boundary of the zone to the water intakes. For example, for zone II it is the time of microbial contamination transport, accepted for target aquifers insufficiently protected from the surface, which is equal to 400 days. For zone III, this is the time of chemical pollution transport equal to the estimated lifetime of the water intake. To calculate the spatial position of the boundaries of these zones, analytical and numerical methods are used based on the integration of equations for the velocities of neutral particles in the groundwater flow, the flow field of which formed by the superposition of the natural flow velocities and the disturbances imposed on it by groundwater abstraction. When these methods are used, the only configuration of the sanitary protection zone that corresponds to some homogeneous or heterogeneous spatial field of hydraulic parameters obtained from field materials and (or) from the solution of the inverse problem is obtained as a result of calculations. At the same time, possible variations of SPZ boundaries are not considered due to local hydraulic heterogeneity, which is not taken into account in the water intake model. The article analyzes the influence of vertical hydraulic heterogeneity on the formation of sanitary protection zones in the layered heterogeneous aquifer. Random stationary fields of normally distributed logarithms of hydraulic conductivity were used as a basis for the model of hydraulic heterogeneity. As a result, the sizes of the first and second zones of sanitary protection were estimated and the comparative analysis of the received values with the sizes of SPZ was carried out, which were determined without taking into account model hydraulic heterogeneity. The analysis showed that the consideration of model hydraulic heterogeneity leads to a significant increase in the sanitary protection zones.
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Rose-Harvey, Keisha, Kevin J. McInnes, and James C. Thomas. "Water Flow Through Sand-based Root Zones Atop Geotextiles." HortScience 47, no. 10 (October 2012): 1543–47. http://dx.doi.org/10.21273/hortsci.47.10.1543.
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An alternative to the time-tested gravel drainage layer beneath a sand-based root zone of a sports field or golf putting green can be constructed from a geotextile atop a highly porous drainage material or structure. The geotextile serves to support the root zone mixture on the drainage layer whose pores can be too large for the sand to support itself by bridging. In such an application, the geotextile should have high enough strength and resistance to stretching to support the root zone mixture atop the pores of the drainage layer and should contain internal pores of appropriate size to retain the bulk of particles in the root zone mixture and to allow free passage of drainage water and eluviating fine particles. The objective of this study was to determine whether geotextiles selected to meet these criteria affect the drainage rates of sand-based root zones and whether they affect the size of particles lost from the root zone–geotextile systems. In a 1-year laboratory study that made use of 150-mm diameter polyvinyl chloride (PVC) test cells, measurements of drainage rates and saturated hydraulic conductivities were made on replicated combinations of 10 geotextiles and three 300-mm deep root zone mixtures. Size distributions and total masses of particles that passed from the root zones through the geotextiles were measured. Statistical analyses showed that drainage rate, saturated hydraulic conductivity, and size distribution and mass of eluviated particles were unaffected by the properties of the geotextiles. The results gave of no reason to prohibit the use of geotextiles to support sand-based root zones in golf putting greens or sports fields.
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Pagnozzi, Mauro, Gianluca Coletta, Guido Leone, Vittorio Catani, Libera Esposito, and Francesco Fiorillo. "A Steady-State Model to Simulate Groundwater Flow in Unconfined Aquifer." Applied Sciences 10, no. 8 (April 14, 2020): 2708. http://dx.doi.org/10.3390/app10082708.
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The hydraulic and hydrogeological features of the Caposele aquifer have been investigated by using a numerical groundwater flow model. In particular, groundwater flow simulations were performed for a multilayered, unconfined aquifer in steady-state conditions for different thicknesses of the aquifer’s saturated zone. The Caposele groundwater model was carried out starting from a generic model drained by a unique spring outlet in accordance with the geo-hydrological features of the study area. The conceptual model was built considering hydrogeological features of spring catchment, and was then implemented with the MODFLOW numerical code. A combined 2D-3D approach was adopted, and the model was calibrated on borehole data available for the time period 2012–2019. Different thicknesses of the aquifer were set, and a reliable relationship was found between the hydraulic head, saturated zone and hydraulic conductivity of the aquifer. Using the MODPATH package, the mean travel time (Darcian) of groundwater was computed for five different scenarios, corresponding to the model’s depths; the analysis that was performed shows that the travel time is higher for a greater and lower for a smaller thickness of the aquifer’s saturated zone, respectively. The Caposele aquifer model was zoned in different sectors, named flow pipe areas, that play different roles in groundwater recharge-discharge processes. A vector analysis was also carried out in order to highlight the ascendant flow near the spring zone.
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Dethier, David P., Noah Williams, and Jordan F. Fields. "Snowmelt-Driven Seasonal Infiltration and Flow in the Upper Critical Zone, Niwot Ridge (Colorado), USA." Water 14, no. 15 (July 26, 2022): 2317. http://dx.doi.org/10.3390/w14152317.
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The hydrology of alpine and subalpine areas in the Colorado Front Range (USA) is evolving, driven by warming and by the alteration of precipitation patterns, the timing of snowmelt, and other components of the hydrologic budget. Field measurements of soil hydraulic conductivity and moisture along 30-m transects (n = 13) of representative soils developed in surficial deposits and falling head slug tests of shallow groundwater in till demonstrate that hydraulic conductivity in the soil is comparable to hydraulic conductivity values in the shallow aquifer. Soil hydraulic conductivity values were variable (medians ranged from 5.6 × 10−7 to 4.96 × 10−5 m s−1) and increased in alpine areas underlain by periglacial deposits. Hydraulic conductivities measured by a modified Hvorslev technique in test wells ranged from 4.86 × 10−7 to 1.77 × 10−4 m s−1 in subalpine till. The results suggest a gradient from higher hydraulic conductivity in alpine zones, where short travel paths through periglacial deposits support ephemeral streams and wetlands, to lower hydraulic conductivity in the till-mantled subalpine zone. In drier downstream areas, streambed infiltration contributes substantially to near-channel groundwater. As summer temperatures and evapotranspiration (ET) increase and snowmelt occur earlier, alpine soils are likely to become more vulnerable to drought, and groundwater levels in the critical zone may lower, affecting the connectivity between late-melting snow, meltwater streams, and the areas they affect downstream.
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Ranieri, E. "Hydraulics of sub-superficial flow constructed wetlands in semi arid climate conditions." Water Science and Technology 47, no. 7-8 (April 1, 2003): 49–55. http://dx.doi.org/10.2166/wst.2003.0670.
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This paper reports the evaluation of the hydraulics of two constructed wetland (cws) plants located in Apulia (the South Eastern Italy region characterized by semi arid climate conditions). These fields were planted with Phragmites australis hydrophytes and are supplied with local secondary wastewater municipal treatment plant effluent. Each plant - Kickuth Root-Zone method based - covers an area of approx. 2,000 m2. The evapotranspiration phenomenon has been evaluated within perforated tubes fixed to the field bottom and very high values - up to 40 mm/d - were found. Hydraulic conductivity has been evaluated by in situ measurements at different field points. Hydraulic gradients and the piezometric curve within the field are also reported.
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Luo, Can, Hao Liu, Li Cheng, Chuan Wang, Weixuan Jiao, and Di Zhang. "Unsteady Flow Process in Mixed Waterjet Propulsion Pumps with Nozzle Based on Computational Fluid Dynamics." Processes 7, no. 12 (December 3, 2019): 910. http://dx.doi.org/10.3390/pr7120910.
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The unsteady flow process of waterjet pumps is related to the comprehensive performance and phenomenon of rotating stall and cavitation. To analyze the unsteady flow process on the unsteady condition, a computational domain containing nozzle, impeller, outlet guide vane (OGV), and shaft is established. The surface vortex of the blade is unstable at the valley point of the hydraulic unstable zone. The vortex core and morphological characteristics of the vortex will change in a small range with time. The flow of the best efficiency point and the start point of the hydraulic unstable zone on each turbo surface is relatively stable. At the valley point of the hydraulic unstable zone, the flow and pressure fields are unstable, which causes the flow on each turbo surface to change with time. The hydraulic performance parameters are measured by establishing the double cycle test loop of a waterjet propulsion device compared with numerical simulated data. The verification results show that the numerical simulation method is credible. In this paper, the outcome is helpful to comprehend the unsteady flow mechanism in the pump of waterjet propulsion devices, and improve and benefit their design and comprehensive performance.
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Peng, Li, Wang Kai, Li Bo, Jiang Yifeng, and Gou Jianqiang. "Research on the Effective Influence Radius of Hydraulic Reaming in Mining Seam." Open Fuels & Energy Science Journal 8, no. 1 (July 31, 2015): 161–67. http://dx.doi.org/10.2174/1876973x01508010161.
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In Accordance with the present situations suggesting that the construction of the gas drainage boreholes in mining seam is sufficient and the gas drainage effect in low permeability coal seams does not yield perfectly, the hydraulic reaming technology in mining seam was proposed to increase the gas drainage efficiency. Through the gas flow method, the effective influence radius of hydraulic reaming was determined and the fluid-solid coupling model of gas drainage along boreholes after hydraulic reaming was established theoretically. Following this, the changes in the laws of gas content around the boreholes in the coal seam were simulated and analyzed. The results indicated that hydraulic reaming can effectively promote the stress-relief and permeability-increase of the coal mass around the boreholes, and the coal mass around the reaming boreholes can be divided into gas flow increase zone, gas flow delay attenuation zone and fast decay zone. The effective influence radius of hydraulic reaming was 5.5~6 m. The obtained simulation results were basically in accordance with the field investigation.
Dissertations / Theses on the topic "Hydraulic flow zone"
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Don, Fransiskuge Perera Eranda Chinthaka. "Surface-groundwater flow modelling in the swash zone." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/55223/.
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This research work is aimed at developing a coupled surface-groundwater flow model which can be used to simulate both surface and groundwater flow at the swash zone. The coupled model is then used to investigate the effects of seepage on swash hydrodynamics as well as morphodynamics. The surface flow model was originally developed by Briganti et al. (2012), which solved a system of equations consisting of the Nonlinear Shallow Water Equations and the bed-evolution (Exner) equation with bed shear stress computed using a boundary layer model without seepage developed in Briganti et al. (2011). In this work, a groundwater flow model which solves Laplace's equation following the approach of Li and Barry (2000) is incorporated into the surface flow model, which allows computation of seepage into the bed (infiltration) and out of it (exfiltration). The seepage is then included into the boundary layer models to incorporate the effects of seepage on the bed shear stress. To assess the performance of the surface flow model, dam-break cases are simulated and compared against analytical and quasi-analytical solutions from literature. Firstly, the dam-break case on a fixed bed is simulated and compared against Ritter solution (Stoker, 1957) and then the dam-break case on a mobile bed is verified against Zhu (2012)'s quasi-analytical Riemann solver. Both models show good agreement with their respective reference results. Subsequently, the verification of the groundwater flow model is conducted by simulating phreatic surface flow through a rectangular dam and comparing the results against those of Kazemzadeh-Parsi and Daneshmand (2012). Next, the coupled surface-groundwater flow model is validated by reproducing surface and groundwater flow in the prototype-scale BARDEX II experiment. Firstly, the groundwater flow cases (higher and lower lagoon levels than the initial sea level) without surface water waves are simulated. The comparison of time-averaged numerical phreatic surface elevations against the experimental data shows excellent agreement. Next, the surface water waves are included and the simulations are repeated for the previous two cases. The groundwater comparisons again yield good agreement and the hydrodynamics of the surface waves show reasonably close agreement. Increase in exfiltration is observed to result in an increase in boundary layer thickness, which subsequently results in smaller velocity gradients and a decrease in bed shear stress using exfiltration included BBL model of Cheng and Chiew (1998). Conversely, the increase in infiltration causes a decrease in boundary layer thickness, which results in an increase in bed shear stress using infiltration included BBL model of Chen and Chiew (2004). The model results also show that the boundary layer effect by infiltration is opposed by the 'continuity effect' in the swash zone (Baldock and Nielsen, 2009). The model results show that an increase in infiltration rates is observed to increase slip velocity, and also compares well against the empirical equation derived in Chen and Chiew (2004). Furthermore, the rate of increase (decrease) of bed shear stress due to infiltration (exfiltration) compares favourably against the empirical trend line of Nielsen et al. (2001) and experimental data of Conley (1993). Additionally, the boundary layer model bed shear stress is compared against single swash event bed shear stress results from Kikkert et al. (2013) experiment and shows reasonably good agreement. The boundary layer models can be used to account for seepage effects on bed shear stressfor a larger range of ventilation parameters than Nielsen et al. (2001), which would improve morphodynamical modelling on permeable beds in the swash zone. Finally, the performance of the coupled surface-groundwater model is further investigated by simulating the BARDEX II experiment with a mobile bed. The swash zone water depth compares well with the BARDEX II experimental results. Although the corresponding dataset for velocity is shown to be rather unreliable during backwash, during uprush, the comparison is very close. Using both Meyer-Peter-Müller (MPM) and Grass sediment transport models, similar morphodynamical patterns are observed. The bed change comparisons against experimental results show that the model predicts the same order as well as the same pattern of erosion. However, deposition in the upper swash zone is not predicted by the model which could be due to the presence of significant amounts of suspended sediment which would lead to onshore sediment transport (Pritchard and Hogg, 2005, Zhu and Dodd, 2015) which is not accounted for in the simplified numerical model. The model is shown to be robust and flexible and it is capable of simulating both surface and groundwater flow simultaneously on fixed or evolving bed.
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Horobin, Richard. "The use of geophysical methods in defining the fracture characteristics and hydraulic mechanisms in the chalk." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325130.
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Zhang, Yonggen, Marcel G. Schaap, Alberto Guadagnini, and Shlomo P. Neuman. "Inverse modeling of unsaturated flow using clusters of soil texture and pedotransfer functions." AMER GEOPHYSICAL UNION, 2016. http://hdl.handle.net/10150/622504.
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Characterization of heterogeneous soil hydraulic parameters of deep vadose zones is often difficult and expensive, making it necessary to rely on other sources of information. Pedotransfer functions (PTFs) based on soil texture data constitute a simple alternative to inverse hydraulic parameter estimation, but their accuracy is often modest. Inverse modeling entails a compromise between detailed description of subsurface heterogeneity and the need to restrict the number of parameters. We propose two methods of parameterizing vadose zone hydraulic properties using a combination of k-means clustering of kriged soil texture data, PTFs, and model inversion. One approach entails homogeneous and the other heterogeneous clusters. Clusters may include subdomains of the computational grid that need not be contiguous in space. The first approach homogenizes within-cluster variability into initial hydraulic parameter estimates that are subsequently optimized by inversion. The second approach maintains heterogeneity through multiplication of each spatially varying initial hydraulic parameter by a scale factor, estimated a posteriori through inversion. This allows preserving heterogeneity without introducing a large number of adjustable parameters. We use each approach to simulate a 95 day infiltration experiment in unsaturated layered sediments at a semiarid site near Phoenix, Arizona, over an area of 50 x 50 m(2) down to a depth of 14.5 m. Results show that both clustering approaches improve simulated moisture contents considerably in comparison to those based solely on PTF estimates. Our calibrated models are validated against data from a subsequent 295 day infiltration experiment at the site.
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Fang, Zhufeng. "USING GEOSTATISTICS, PEDOTRANSFER FUNCTIONS TO GENERATE 3D SOIL AND HYDRAULIC PROPERTY DISTRIBUTIONS FOR DEEP VADOSE ZONE FLOW SIMULATIONS." Thesis, The University of Arizona, 2009. http://hdl.handle.net/10150/193439.
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We use geostatistical and pedotrasnfer functions to estimate the three-dimensional distributions of soil types and hydraulic properties in a relatively large volume of vadose zone underlying the Maricopa Agriculture Center near Phoenix, Arizona. Soil texture and bulk density data from the site are analyzed geostatistically to reveal the underlying stratigraphy as well as finer features of their three-dimensional variability in space. Such fine features are revealed by cokriging soil texture and water content measured prior to large-scale long-term infiltration experiments. Resultant estimates of soil texture and bulk density data across the site are then used as input into a pedotransfer function to produce estimates of soil hydraulic parameter (saturated and residual water content θs and θr, saturated hydraulic conductivity Ks, van Genuchten parameters αand n) distributions across the site in three dimensions. We compare these estimates with laboratory-measured values of these same hydraulic parameters and find the estimated parameters match the measured well for θs, n and Ks but not well for θr nor α, while some measured extreme values are not captured. Finally the estimated soil hydraulic parameters are put into a numerical simulator to test the reliability of the models. Resultant simulated water contents do not agree well with those observed, indicating inverse calibration is required to improve the modeling performance. The results of this research conform to a previous work by Wang et al. at 2003. Also this research covers the gaps of Wang’s work in sense of generating 3-D heterogeneous fields of soil texture and bulk density by cokriging and providing comparisons between estimated and measured soil hydraulic parameters with new field and laboratory measurements of water retentions datasets.
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Benton, Joshua Robert. "Temporal Dynamics of Groundwater Flow Direction in a Glaciated, Headwater Catchment." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/104222.
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Shallow groundwater flow in the critical zone of steep headwater mountain catchments is often assumed to mimic surface topography. However, groundwater flow is influenced by other variables, such as the elevation of the water table and subsurface hydraulic conductivity, which can result in temporal variations in both magnitude and direction of flow. In this study, I investigated the temporal variability of groundwater flow in the soil zone (solum) within the critical zone of a headwater catchment at the Hubbard Brook Experimental Forest in North Woodstock, NH. Groundwater levels were continuously monitored throughout several seasons (March 2019 to Jan 2020) in a network of wells comprising three hillslope transects within the upper hillslopes of the catchment. Five clusters of three wells per cluster were screened from 0.18 – 1.1 m depth at the base of the solum. Water levels were also monitored in five deeper wells, screened from 2.4 - 6.9 m depth within glacial sediments of the C horizon. I conducted 47 slug tests across the well network to determine hydraulic properties of the aquifer materials surrounding each well. In addition, our team conducted a large-scale auger investigation mapping soil horizon depths and thicknesses.
Results show that the magnitude of hydraulic gradients and subsurface hydrologic fluxes varied at each site with respect to changing water-table elevation, having a maximum range of 0.12 m/m and 9.19 x 10-6 m/s, respectively. The direction of groundwater flow had an arithmetic mean deviating from surface topography by 2-10 degrees, and a total range that deviated from surface topography by as much as 51 degrees. During lower water table regimes, groundwater flow direction deviated from the ground surface, but under higher water table regimes, in response to recharge events, flow direction mimicked surface topography. Within most of the well clusters, there is an observable connection between the slope direction of the top of the C horizon and the direction of groundwater flow during lower water table regimes. Slug test results show the interquartile range of saturated hydraulic conductivity (K¬sat¬) within the C horizon (1.5×10-7 to 9.8×10-7 m/s) is two orders of magnitude lower than the interquartile range of K¬sat¬ values within the solum (2.9×10-5 to 5.2×10-5 m/s). Thus, the C horizon is on average a confining unit relative to the solum that may constrict groundwater flow below the solum. Additionally, results from the larger scale auger investigation suggest that deviations in subsurface topography of the C horizon may be generalizable at the larger hillslope scale. Overall, these results indicate that 1) shallow groundwater flow direction and magnitude within this headwater catchment are dynamic and can deviate from surface topography, and 2) the subsurface topography of the C horizon can influence groundwater flow direction. These results imply that temporal dynamics of groundwater flow direction and magnitude should be considered when characterizing subsurface flow in critical zone studies. Additionally, knowledge of subsurface topography of confining units may provide constraints on the temporal variability of groundwater flow direction.M.S.
Streams that originate at higher elevations (defined as headwater streams) are important drinking water sources and deliver water and nutrients to maintain freshwater ecosystems. Groundwater is a major source of water to these streams, but little is known about how groundwater flows in these areas. Scientists delineate watersheds (areas of land that drain water to the same point) using surface topography. This approach works well for surface water, but not as well for groundwater, as groundwater may not flow in the same direction as surface water. Thus, assuming that the ground-watershed is the same as the surface watershed can lead to errors in hydrologic studies. To obtain more accurate information about groundwater flow in headwater areas, I continuously measured groundwater levels in forest soils at the Hubbard Brook Experimental Forest in North Woodstock, NH. My main objective was to determine if there is variability in the direction and amount of groundwater flow. I also measured the characteristics of the soils to identify the thicknesses of soil units and the permeability of those units. I used these data to evaluate the relationship between groundwater flow direction, surface topography, and the permeability of soil units. Overall, I found that groundwater flow direction can differ significantly from surface topography, and groundwater flow direction was influenced by the groundwater levels. When groundwater levels were high (closer to the land surface), groundwater flow was generally in the same direction as surface topography. However, when groundwater levels were lower, flow direction typically followed the slope of the lowest permeability soil unit. These results suggest that scientists should not assume that groundwater flow follows the land surface topography and should directly measure groundwater levels to determine flow direction. In addition, results from this study show that characterizing soil permeability can help scientists make more accurate measurements of groundwater flow.
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Menichino, Garrett Thomas. "Preferential and Non-Darcy Flows in the Hyporheic Zone: Surface Water-Groundwater Hydraulics and Effects on Stream Functions." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/52358.
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Surface water-groundwater interaction can provide various stream functions including temperature regulation, nutrient cycling, pollutant attenuation, and habitat creation. However previous literature is divided on the extent and conditions of these benefits. This dissertation has explored the dominance of hydraulic conductivity (K) on hyporheic hydraulics and implications to hyporheic zone functions through a series of modeling studies and field experiments.
Computational Fluid Dynamics (CFD) software was used to model the effect of varying K on weir-induced hyporheic exchange hydraulics and heat transport. Fundamental shifts in hydraulics and temperature dynamics occurred at threshold K's. Surface water began noticeably sinking into the bed above a threshold of K=10-3 m/s and inertial forces caused deviation from Darcy's Law. The heat transport model indicated net downstream surface water cooling from weir-induced 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 functions dependent on flow-rate or residence time.
The importance of macropores to hyporheic transport through meander bends was explored. Transport velocities, hydraulic head gradients, and solute transport rates through the meander bend were increased by macropores. Results indicate that macropores can dictate solute or pollutant transport through meander bends and in the hyporheic zone, which in turn may influence biogeochemical cycling and pollutant attenuation.
Surface-connected macropores along streams were studied as hydrologically important subsurface heterogeneities for surface water-groundwater interaction. Macropores were common geomorphic features in the Appalachian province of southwestern Virginia, and were inundated during storm events over a one-year period. Banks with macropores experienced increased hydraulic head fluctuations, temperature fluctuations, and K. Macropores increased bank storage rates and solute transport between the channel and riparian groundwater zones, which in turn may influence biogeochemical cycling, pollutant attenuation, and hyporheic habitat. Macropores may be important to hyporheic flow and solute transport in a wide range of conditions and may broaden the portion of the landscape in which hyporheic exchange is important. Future work is needed to further assess the impacts of macropores on hyporheic functions and explore new methods to map and quantify macropore geometries and inter-connectivity.Ph. D.
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McEwen, Amiana Marie. "Abundance, Distribution, and Geometry of Naturally Occurring Macropores in Stream Banks." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/95948.
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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 and forest soils, often as a result of biological and physical processes. Macropores also exist in stream banks and have the potential to enhance the exchange of water and solutes between the channel and riparian groundwater, yet the geographic distribution of bank macropores is unknown. Here we determined the abundance, distribution, and geometry of naturally occurring surface-connected macropores in the banks of 20 streams across five physiographic provinces in the Eastern United States. We identified a total of 1,748 macropores, which were present in all 20 streams, with 3.8 cm average width, 3.3 cm average height, 11.5 cm average depth, and 27.9 cm average height above water surface elevation. Macropore abundance, distribution and geometry were statistically different between physiographic provinces, stream orders, and soil textures, with the latter being the most important. Macropores tended to be larger and more abundant in soils with a high cohesiveness and a low hydraulic conductivity compared to soils with a low cohesiveness and high hydraulic conductivity. As a result, streams with greater longitudinal heterogeneity of soil texture also had greater heterogeneity of macropore density. However, macropore size and height above baseflow water surface elevation also increased with stream order and therefore stream size. This work represents the first attempt to characterize macropores across a variety of riverine systems and presents evidence that macropores may play an important role in hyporheic exchange within stream banks. These results may have water quality implications, where macropores may enhance hyporheic exchange yet reduce the filtering capacity of riparian buffer zones.MS
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Festger, Adam Douglas. "Analysis of hydraulic capture zones and efficiency under time-varying flow and pumping conditions." Thesis, The University of Arizona, 2000. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_2000_30_sip1_w.pdf&type=application/pdf.
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Quadri, Marintho Bastos. "L'infiltrométrie multi-disques pour la caractérisation hydro-dispersive des sols non saturés : modélisation des transferts et applications." Grenoble 1, 1993. http://www.theses.fr/1993GRE10100.
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L' attention, tout au long de ce mémoire est principalement dirigée vers l'infiltrométrie multi-disques appliquée aux problèmes de transfert multidirectionnel d'eau et de solute partiellement satures en eau. Les aspects étudiés, notamment pour les applications in-situ, englobent la précision et la sensibilité de la méthode, le phénomène de l'encroutement des sols, et le problème du contact hydraulique entre l'infiltromètre et le sol. Actuellement, la méthode appelée trims (triple ring infiltrometers at multiple succion), selon la dénomination introduite par le lthe, est utilisée avec trois disques de rayons différents. Ce contexte impose l'étude de la solution quasi-linéaire de l'infiltration en régime stationnaire proposée par Wooding (1968). Afin de vérifier l'applicabilité de cette solution lorsque les hypothèses de linéarisation ne sont pas respectées, les équations de transfert macroscopiques sont résolues par la méthode des différences finies en considérant une géométrie axisymétrique. Une fois examiné l'aspect hydrodynamique, le transport d'un solute non interactif (traceur) est modélisé en tenant compte des mécanismes de dispersion-convection. L'introduction d'un solute dans l'écoulement à l'aide de l'infiltromètre apparaît comme une approche séduisante pour l'étude des propriétés hydro-dispersives et pour la caractérisation plus fine du régime d'écoulement. On conclut que l'infiltrométrie multi-disques couplée (ou non) à des techniques complémentaires d'échantillonnage et de mesures en laboratoire constitue une approche incontestablement intéressante pour l'étude suscitée. De plus, le modèle-simulateur semble constituer un outil d'aide à la méthode de caractérisation dans la mesure où il peut conférer une plus grande crédibilité aux estimations expérimentales. Il reste encore à souligner que l'approche adoptée ici représente néanmoins une vue très simpliste face à l'énorme complexité de la réalité physique. Toutefois, il parait évident que, dans les limites d'applicabilité du modèle, les résultats obtenus ont permis de mettre en évidence certaines tendances tout à fait réalistes
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Biniwale, Shripad. "Hydraulic flow zone unit characterisation and mapping for Australian geological depositional environments." Thesis, 2005. http://hdl.handle.net/2440/82098.
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Prediction of reservoir productivity and petroleum recovery efficiency requires detailed analysis of various reservoir properties and their interrelationship. Among fundamental data used in such analysis, core data occupies a significant place in characterizing reservoirs. Core data is used in laboratory measurements to obtain basic and special formation parameters and plays a vital role in terms of understanding geological depositional environments and subsequent alteration (diagenesis). Geoscientists have traditionally classified rocks according to porosity, grain parameters (size, sorting and distribution) whereas reservoir engineers tend to emphasize the dynamic behaviour of multiphase flow in rock formations (relative permeability and capillary pressure). To bridge such differing views, the Carman-Kozeny (C-K) equation based Hydraulic Flow Zone Unit (HU or FZIJ) methodology, which considers variation in flow behaviour properties as a function of geological facies, has been found ideal in characterizing very diverse Australian reservoirs. Compared to previous studies, which tended to classify formations firstly by rock parameters, this research work shows the advantages of classifying formations firstly according to geological deposition and secondly by rock parameters. For this purpose, the concept of 'Global Characteristic Envelopes' (GCEs) has been introduced which groups data by specific geological environments. Several such envelopes can be created for different fields, where the internal structure of each envelope is a function of rock parameters, influenced by variation in deposition and subsequent diagenetic effects, such as compaction, cementation and mineralization (e.g. formation of clays). As a specific application that uses the above methodology, laboratory derived capillary pressure data, for a number of Australian offshore fields, has been reviewed for the purpose of establishing water saturation-height relationships as a function of rock type, forming part of a comprehensive petrophysical analysis. A modified 'FZI-λ' method, capable of giving improved estimates of reservoir fluid distributions, has been proposed. The new methodology is particularly well suited for interpolating among different lithologies and diverse rock types as evident from comparison with other methods reported in the literature. In conclusion, this work demonstrates the multidisciplinary approach to reservoir characterisation, a requirement for a more comprehensive understanding of reservoirs. This systematic approach, utilizing FZIJs, has resulted in an overall improved methodology that is able to integrate geological, petrophysical and engineering aspects.Thesis (M.Eng.Sc.) -- University of Adelaide, Australian School of Petroleum, 2005
Books on the topic "Hydraulic flow zone"
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Perkins, Kim S. Measurement of hydraulic properties of the B-C interbed and their influence on contaminant transport in the unsaturated zone at the Idaho National Engineering and Environmental Laboratory, Idaho. Idaho Falls, Idaho: U.S. Dept. of the Interior, U.S. Geological Survey, 2000.
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Gourlay, M. R. Wave set-up, wave run-up, and beach water table: Interaction between surf zone hydraulics and groundwater hydraulics. St. Lucia, Q: Dept. of Civil Engineering, University of Queensland, 1990.
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Gourlay, M. R. Wave set-up,wave run-up and beach water table: Interaction between surf zone hydraulics and groundwater hydraulics. St. Lucia: University of Queensland, Dept. of Civil Engineering, 1990.
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San Antonio Water System (Tex.) and Geological Survey (U.S.), eds. Lithologic and physicochemical properties and hydraulics of flow in and near the freshwater/saline-water transition zone, San Antonio segment of the Edwards Aquifer, south-central Texas, based on water-level and borehole geophysical log data, 1999-2007. Reston, Va: U.S. Dept. of the Interior, U.S. Geological Survey, 2010.
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Szymkiewicz, Adam. Modelling Water Flow in Unsaturated Porous Media: Accounting for Nonlinear Permeability and Material Heterogeneity. Springer London, Limited, 2012.
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Szymkiewicz, Adam. Modelling Water Flow in Unsaturated Porous Media: Accounting for Nonlinear Permeability and Material Heterogeneity. Springer Berlin / Heidelberg, 2014.
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Szymkiewicz, Adam. Modelling Water Flow in Unsaturated Porous Media: Accounting for Nonlinear Permeability and Material Heterogeneity. Springer, 2012.
Find full textBook chapters on the topic "Hydraulic flow zone"
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Shankar, Daya, Harabindu Debnath, and Indira Kar. "Parametric Analysis of Coupled Thermal Hydraulic Instabilities in Forced Flow Channel Using Reduced-Order Three-Zone Model." In Lecture Notes in Mechanical Engineering, 87–99. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-7831-1_9.
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Gray, William G., and Michael A. Celia. "Incorporation of Interfacial Areas in Models of Two-Phase Flow." In Vadose Zone Hydrology. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195109900.003.0006.
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The mathematical study of flow in porous media is typically based on the 1856 empirical result of Henri Darcy. This result, known as Darcy’s law, states that the velocity of a single-phase flow through a porous medium is proportional to the hydraulic gradient. The publication of Darcy’s work has been referred to as “the birth of groundwater hydrology as a quantitative science” (Freeze and Cherry, 1979). Although Darcy’s original equation was found to be valid for slow, steady, one-dimensional, single-phase flow through a homogeneous and isotropic sand, it has been applied in the succeeding 140 years to complex transient flows that involve multiple phases in heterogeneous media. To attain this generality, a modification has been made to the original formula, such that the constant of proportionality between flow and hydraulic gradient is allowed to be a spatially varying function of the system properties. The extended version of Darcy’s law is expressed in the following form: qα=-Kα . Jα (2.1) where qα is the volumetric flow rate per unit area vector of the α-phase fluid, Kα is the hydraulic conductivity tensor of the α-phase and is a function of the viscosity and saturation of the α-phase and of the solid matrix, and Jα is the vector hydraulic gradient that drives the flow. The quantities Jα and Kα account for pressure and gravitational effects as well as the interactions that occur between adjacent phases. Although this generalization is occasionally criticized for its shortcomings, equation (2.1) is considered today to be a fundamental principle in analysis of porous media flows (e.g., McWhorter and Sunada, 1977). If, indeed, Darcy’s experimental result is the birth of quantitative hydrology, a need still remains to build quantitative analysis of porous media flow on a strong theoretical foundation. The problem of unsaturated flow of water has been attacked using experimental and theoretical tools since the early part of this century. Sposito (1986) attributes the beginnings of the study of soil water flow as a subdiscipline of physics to the fundamental work of Buckingham (1907), which uses a saturation-dependent hydraulic conductivity and a capillary potential for the hydraulic gradient.
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Parlance, J. Y., and T. S. Steenhuis. "Soil Properties and Water Movement." In Vadose Zone Hydrology. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195109900.003.0008.
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For all spatial scales, from pore through local and field, to a watershed, interaction of the land surface with the atmosphere will be one of the crucial topics in hydrology and environmental sciences over the forthcoming years. The recent lack of water in many parts of the world shows that there is an urgent need to assess our knowledge on the soil moisture dynamics. The difficulty of parameterization of soil hydrological processes lies not only in the nonlinearity of the unsaturated flow equation but also in the mismatch between the scales of measurements and the scale of model predictions. Most standard measurements of soil physical parameters provide information only at the local scale and highlight the underlying variability in soil hydrological characteristics. The efficiency of soil characteristic parameterization for the field scale depends on the clear definition of the functional relationships and parameters to be measured, and on the development of possible methods for the determination of soil characteristics with a realistic use time and effort. The soil’s hydraulic properties that affect the flow behavior can be expressed by a soil water retention curve that describes the relation between volumetric water content, θ(L3L3), and soil water pressure, h(L), plus the relation between volumetric water content and hydraulic conductivity, K(L/T). In the next section, the determination of soil hydraulic parameters is first discussed for local and field scale. Then, we show how the pore-scale processes can be linked to soil hydraulic properties. These properties are then used in some of the modern methods that use integral and superposition solutions of Richards’ equation for infiltration and water flow problems for both stable and preferential types of flows. Finally, some practical aspects for watersheds are discussed to highlight the difficulties encountered when large-scale predictions are needed.
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Mulla, D. J., and A. P. Mallawatantri. "Site-Specific Management of Flow and Transport in Homogeneous and Structured Soils." In Vadose Zone Hydrology. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195109900.003.0019.
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Among research publications in soil science, few have had a greater impact than those by Nielsen et al. (1973) or Biggar and Nielsen (1976). According to Science Citation Index, the former paper, entitled “Spatial variability of field-measured soilwater properties,” has been cited by scientific peers over 390 times. The 1976 paper, entitled “Spatial variability of the leaching characteristics of a field soil,” has been cited over 232 times. Experimental work presented in both papers represents the first-ever attempt at a large field-scale study of steady-state water and solute transport (Wagenet, 1986). Among the seminal findings of these two papers were as follows: (1) extensive spatial variability existed in soil hydraulic and solute transport properties within a relatively homogeneous field (important in the work of Pilgrim et al., 1982; Addiscott and Wagenet, 1985; Feddes et al., 1988; van dcr Molen and van Ommen, 1988); (2) soil water content, bulk density, and soil particle size exhibited normal frequency distributions, while distributions for hydraulic conductivity, hydraulic diffusivity, pore water velocity, and hydrodynamic dispersion were lognormal (work extended by van der Pol et al.. 1977; Rao et al., 1979); (3) frequency distributions were far superior to field-average parameter values (especially for lognormally distributed properties) in describing field transport behavior (demonstrated by Rao et al., 1979; Trangmar et al., 1985); (4) a simple unit hydraulic gradient method was shown to estimate saturated hydraulic conductivity accurately (results extended by Libardi et al., 1980; van Genuchten and Leij, 1992); (5) good correspondence was found between solute velocity and pore water velocity (key assumption in Jury and Fluhler, 1992); (6) and theoretical predictions of a linear relation between hydrodynamic dispersion and pore water velocity were shown to be obeyed at the field scale (result used widely by solute transport modelers, as discussed in Nielsen et al., 1986). The seminal works by Nielsen et al. (1973) and Biggar and Nielsen (1976) produced several new directions in soil science and vadose zone hydrology research. The most interesting was a series of papers that rejected the theoretical basis and practicality of using deterministic equations, and instead introduced stochastic approaches to describe field-scale water and solute fluxes.
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Li, Chen, and Hongming Wang. "Influence of Axial Clearance on Water-Jet Axial Flow Pump." In Advances in Transdisciplinary Engineering. IOS Press, 2021. http://dx.doi.org/10.3233/atde210331.
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Three dimensional Reynolds averaged N-S equation and S-A turbulent model were adopted to simulate the flow field and hydraulic performance of the waterjet axial flow pump with the different impeller axial clearance. The numerical research results show that with the increase of axial clearance size, total pressure and static pressure rise at first and then decreases, torque and shaft power remain basically unchanged, the efficiency decreases gradually, the suction surface separation zone of stator expanded under the design condition. When the axial clearance is 30mm, the pump hydraulic performance and flow field are the best, and stator load distribution is the most uniform. When the axial clearance is 40–50mm the load of the lower part of stator leading edge is reduced greatly, which is not conducive to maintain static blade strength and maintain the stator rectifying action.
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Guan, Yutong, and Xiaonan Tang. "Influence of Partially-Covered Riparian Vegetation on Flow in a Compound Channel." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220956.
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Vegetation is of great importance in hydraulic engineering as it can affect the flow structures of compound channels in many ways, including the velocity profiles, momentum exchange, and shear stress distributions. This complex flow structure in vegetated compound channels has attracted more and more research interests. However, most of the previous studies have been focusing on fully-covered vegetated compound channels, there are little studies on compound channels with partially vegetated floodplain. This research carried out novel experiments to investigate the flow structure of compound channels with partially-covered vegetation on the floodplain. The results showed that the discharge of the main channel decreases as the depth ratio increases. The retardation effect of vegetation on the flow of non-vegetated floodplain region decreases with the increasing water depth. In addition, the vertical velocity profile in the vegetated zone performs differently in various depth ratios, with its velocity taking a maximum around the middle-water depth zone under emergent cases, while being the maximum near the free surface under submerged cases.
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Tyler, Scott W., and Bridget R. Scanlon. "Water and Solute Transport in Arid Vadose Zones : Innovations in Measurement and Analysis." In Vadose Zone Hydrology. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195109900.003.0017.
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Understanding the physics of flow and transport through the vadose zone has advanced significantly in the last three decades. These advances have been made primarily in humid regions or in irrigated agricultural settings. While some of the techniques are useful, many are not suited to arid regions. The fluxes of water and solutes typically found in arid regions are often orders of magnitude smaller than those found in agricultural settings, while the time scales for transport can be orders of magnitude larger. The depth over which transport must be characterized is also often much greater than in humid regions. Rather than relying on advances in applied tracers, arid-zone researchers have developed natural-tracer techniques that are capable of quantifying transport over tens to thousands of years. Techniques have been developed to measure the hydraulic properties of sediments at all water contents, including the very dry range and at far greater depths. As arid and semiarid regions come under increased development pressures for such activities as hazardous- and radioactive-waste disposal, the development of techniques and the understanding of water and solute transport have become crucial components in defining the environmental impacts of activities at the landsurface. In the past, the movement of water and solutes through the unsaturated zones of arid and semiarid regions was largely ignored, either for the sake of expediency or from a lack of knowledge or misperceptions regarding the extent of water movement. In the High Plains of the United States, water extraction from the Ogallala aquifer proceeded at a rapid rate throughout the 20th century, with little attention paid to the rate of replenishment from natural recharge. As withdrawals began to exceed recharge, water levels dramatically declined and are now necessitating changes in the economic base for this large portion of the agricultural United States. At Hanford, Washington, large amounts of radioactive waste from nuclear weapons production were disposed of at or near the landsurface under the premise that there was no movement of water within the unsaturated zone to transport the contaminants to the underlying aquifer.
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Mimoun, D., S. Gaur, and D. Graillot. "Multi-Criteria Decision Analysis for Identifying a Suitable Location for Groundwater Pumping Wells." In Geographic Information Systems, 736–49. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2038-4.ch045.
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The paper presents the methodology for the combined use of GIS-based multi-criteria analysis and simulation-optimisation modelling for management of the groundwater resources of the Dore river basin in France. The study identifies the suitable location and maximum discharge for the new groundwater pumping wells. The multi-criteria analysis (MCA), with the help of GIS-based geospatial analysis, was performed to identify those areas suitable for pumping wells by considering different criteria, such as hydraulic conductivity, land use, river aquifer exchange, depth to water, and geomorphology. Different criteria were selected with the help of regional experts and stakeholders. For the study area, the groundwater flow model was developed. Further, new pumping wells in the suitable zones, those identified by MCA, were considered and a simulation-optimisation technique was used to identify the maximum discharge from those wells. Finally, the results obtained from both the methods were to finalise the potential zone. The developed methodology proves to be a more realistic approach to identifying new locations for pumping wells.
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"Flow Controlling Reactive Zone Designs." In Remediation Hydraulics, 391–406. CRC Press, 2008. http://dx.doi.org/10.1201/9781420006841-20.
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"Flow Controlling Reactive Zone Designs." In Remediation Hydraulics, 369–84. CRC Press, 2008. http://dx.doi.org/10.1201/9781420006841.ch14.
Full textConference papers on the topic "Hydraulic flow zone"
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Ohmoto, Terunori, Takayuki Okamoto, and Takanobu Nakashima. "Three-Dimensional Flow Structure in an Open Channel with a Flexible Vegetation Zone." In Hydraulic Measurements and Experimental Methods Specialty Conference (HMEM) 2002. Reston, VA: American Society of Civil Engineers, 2002. http://dx.doi.org/10.1061/40655(2002)21.
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Akbar, M. K., D. A. Plummer, and S. M. Ghiaasiaan. "Gas-Liquid Two-Phase Flow Regimes in Microchannels." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-39555.
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Recent experimental data dealing with gas-liquid two-phase flow regimes and their transitions in microchannels with circular and near-circular cross-sections are reviewed and compared. It is shown that, for microchannels with hydraulic diameters close to 1 mm, the available data are in good agreement. These data are used as the basis for the development of a simple Weber number-based flow regime map that divides the entire flow map into four zones: a surface tension dominated zone including bubbly and plug flow patterns; an inertia dominated zone representing the annular flow regime; a dispersed/churn flow zone; and a transition zone that consists of other intermittent flow patterns. Comparison is als o made with the limited available data representing channels with slightly larger hydraulic diameters or different cross-sectional geometries, and the effects of channel cross-sectional geometry and size are examined and discussed. The areas in need of further systematic experimental investigation are identified.
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Frizzell, Carl, and David Werth. "Flow Separation at 90-Degree Junctions With Opposing Flows." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45302.
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Sumps located on the side of cooling tower basins, or any other type of hydraulic structure where opposing flows combine and turn 90-degrees can result in a significant amount of flow separation and energy dissipation at the junction. These separation zones can result in localized regions of higher velocity. If the separation zone is large enough, the flow can approach critical depth. A theoretical method of predicting the size of these separation zones is presented based on the conservation of energy and momentum. To validate the model, the results of an ongoing experimental study are compared to the theoretical predictions. A physical model was constructed and an Acoustic Doppler Velocimeter was used to collect 3-dimensional velocity data within each leg of the junction.
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Bryant, Eric C., Jongsoo Hwang, and Mukul M. Sharma. "Arbitrary Fracture Propagation in Heterogeneous Poroelastic Formations Using a Finite Volume-Based Cohesive Zone Model." In SPE Hydraulic Fracturing Technology Conference. SPE, 2015. http://dx.doi.org/10.2118/spe-173374-ms.
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Abstract A finite volume-based arbitrary fracture propagation model is used to simulate fracture growth and geomechanical stresses during hydraulic fracture treatments. Single-phase flow, poroelastic displacement, and in-situ stress tensor equations are coupled within a poroelastic reservoir domain, using a fixed-strain split assumption. The domain is idealized as two-dimensional and plane-strain, with heterogeneous elastic material and fracture toughness properties. Fracture propagation proceeds by failure along finite volume cells in excess of a threshold effective stress. The cohesive zone model (CZM) is used to simulate propagation of non-planar fractures in heterogeneous porous media under uniform, anisotropic stresses. In addition the model computes the stress field and the pore pressure in the rock matrix to account for stress interference effects. This allows us to estimate the simulated micro-seismic signature of the rock during fracturing. Results show that the presence of bedding planes or planes of weakness in the rock can lead to complex fracture trajectories. The growth of multiple, non-intersecting, competing fractures is also simulated. It is shown that the fracture geometry obtained using this model is highly dependent on the pattern of heterogeneity. For homogeneous reservoirs and a high in-situ stress contrast, planar fractures are obtained. As the stress contrast is decreased and the degree of heterogeneity is increased, fracture complexity increases. Results for different kinds and levels of formation heterogeneity; planes-of-weakness such as bedding planes or natural fracture networks, and layers with different mechanical properties are presented. This model allows for first-of-kind simulation of fracture propagation with arbitrary geometry in a poroelastic solid domain, using proven computational finite volume methods (FVM). The effect of fluid backpressure, mechanical stress shadow effects, and formation heterogeneity are accounted for. The importance of critical stresses on fracture path is discussed.
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Sciortino, Antonella, and Feike J. Leij. "Vertical Flow Aggregation in the Vadose Zone with Spatial- and Cross-Correlated Hydraulic Properties." In World Environmental and Water Resources Congress 2006. Reston, VA: American Society of Civil Engineers, 2006. http://dx.doi.org/10.1061/40856(200)148.
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Aguilar, Cesar, Govea Hugo, and Guillermo Rincón. "Hydraulic Unit Determination and Permeability Prediction Based On Flow Zone Indicator Using Cluster Analysis." In SPE Latin America and Caribbean Petroleum Engineering Conference. Society of Petroleum Engineers, 2014. http://dx.doi.org/10.2118/169307-ms.
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Biniwale, S., and P. Behrenbruch. "The Mapping of Hydraulic Flow Zone Units and Characterisation of Australian Geological Depositional Environments." In SPE Asia Pacific Oil and Gas Conference and Exhibition. Society of Petroleum Engineers, 2004. http://dx.doi.org/10.2118/88521-ms.
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Dontsov, Egor, Roberto Suarez-Rivera, Rohit Panse, Christopher Quinn, Heather LaReau, Kirke Suter, Chris Hines, Ryan Montgomery, and Kyle Koontz. "Ultra-Fast, Pad-Scale Modeling of Hydraulic Fracturing and Depletion for Optimizing Development Plans in the Eagle Ford Play." In SPE Hydraulic Fracturing Technology Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/204151-ms.
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AbstractAs the number of wells drilled in regions with existing producing wells increases, understanding the detrimental impact of these by the depleted zone around parent wells becomes more urgent and important. This understanding should include being able to predict the extent and heterogeneity of the depleted region near the pre-existing wells, the resulting altered stress field, and the effect of this on newly created fractures from adjacent child wells. In this paper we present a workflow that addresses the above concern in the Eagle Ford shale play, using numerical simulations of fracturing and reservoir flow, to define the effect of the depletion zone on child wells and match their field production data. We utilize an ultra-fast hydraulic fracture and depletion model to conduct several hundred numerical simulations, with varying values of permeability and surface area, seeking for cases that match the field production data. Multiple solutions exist that match the field data equally well, and we used additional field production data of parent-child well-interaction, to select the most plausible model. Results show that the depletion zone is strongly non-uniform and that large reservoir regions remain undepleted. We observe two important effects of the depleted zone on fractures from child wells drilled adjacent to the parents. Some fractures propagate towards low pressure zones and do not contribute to production. Others are repelled by the higher stress region that develops around the depletion zone, propagate into undepleted rock, and have production rates commensurate to that from other child wells drilled away from depleted region. The observations are validated by the field data. Results are being used to optimize well placement and well spacing for subsequent field operations, with the objective to increase the effectiveness of the child wells.
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Hurlburt, Evan T., Larry B. Fore, and Richard C. Bauer. "A Two Zone Interfacial Shear Stress and Liquid Film Velocity Model for Vertical Annular Two-Phase Flow." In ASME 2006 2nd Joint U.S.-European Fluids Engineering Summer Meeting Collocated With the 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/fedsm2006-98512.
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The standard approach in estimating the interfacial shear between the vapor and the liquid film in annular two-phase flow is to include the effect of waves using a two-phase friction factor. This has been successful for low pressure annular flows in large hydraulic diameter ducts (wave heights ≪ H/2). It does not, however, work well for high pressure flows in smaller hydraulic diameter ducts (wave heights ∼ H/2). This suggests the need for a more detailed approach to incorporate wave effects in annular flow.
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Kantaatmadja, Budi Priyatna, Fadzlin H. Kasim, W. Nur Zainudin, Emad Elsebakhi, Ernest A. Jones Jr, and Amita M. Ali. "Permeability Prediction Using Rock-Typing, Flow Zone Indicator and Machine Learning Techniques in a Brownfield Offshore Malaysia." In International Petroleum Technology Conference. IPTC, 2021. http://dx.doi.org/10.2523/iptc-21436-ms.
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Abstract Predicting permeability in low-medium quality reservoirs (> 10 md to <100mD) is important in brownfields since many of them can still produce hydrocarbons. Developing an approach relating geologic properties to permeability prediction can increase field reserves and extend producing life. The common practice of predicting permeability includes linear regressions of core-porosities vs. core-permeabilities applying different lithofacies. However, these methods discount data scattering around regression-lines. This paper describes an innovative-technique for permeability prediction that combines rock-types, flow-zone-indicator (FZI), and machine-learning techniques (ML). FZI is a reservoir-flow-unit that controls hydraulic fluid-flow and is influenced by pore-geometry resulting from diagenetic-processes. In reservoirs, pore-geometry usually is heterogenous due to mineral-composition, rock-texture, cementation, and compaction. Thus,the commonly used permeability equation of Kozeny-Carman (KC) equation still can be used but it needs to be modified for better connecting FZI to hydraulic-flow-units. The modified KC equation incorporates heterogeneous poregeometry as a non-linear-function of porosity by adding cementation-exponent (m) into the equation, where the original KC equation assumes m is equal to one. The semi-log cross-plot between Reservoir-Quality-Index (RQI) vs. PHIZ*Por(m-1) (or FZIm) from the modified KC equation can be constructed using rock-type class. The ML approach was applied to predict FZI groups using 4 standard-logs: gamma-ray, resistivity, density, and neutron-porosity. Cross-plots of RQI vs. PHIZ (conventional FZI) can be compared to RQI vs. PHIZ*Por(m-1) (modified FZI model) usingdata from 11cored wells in oil field offshore Malaysia. The modified FZI model shows less data clustering compared to the conventional FZI model, shown by higher R2 coefficient correlation accuracy. The proposed modified FZI model shows narrower permeability range at low porosity which is a good indication of more accurate hydraulic-flow-unit interpretation. When applying the original and modified FZI models, each lithofacies may occur in more than one hydraulic-flow-unit due to pore-geometry difference within the same lithofacies. Furthermore, the hydraulic-flow-unit generated by the modified FZI model is more sensitive to total porosity when comparing to original FZI model. Each generated hydraulic-flow-unit has better correlation to total porosity and with less scattered permeability at the same porosity. The permeability calculated by modified FZI model was then verified with core permeability showing an excellent overall match. On the ML technique, the "Random Forests" technique will be utilized due to recognized as one of the most recent ML algorithm(s) developed as an innovative technique based on both classifications and regression trees techniques. The Random Forests technique has shown its great accuracy on predictive exactness for these challenge permeability estimations. The prediction quality was benchmark by R2 value of > 0.9 for all crossplots (porosity, permeability, and water saturation) when comparing to routine core analysis lab measurements.
Reports on the topic "Hydraulic flow zone"
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Y.S. WU, S. FINSTERLE, AND G. S. BODVARSSON. A FIELD-SCALE MODELING STUDY AND CHARACTERIZING HYDRAULIC PROPERTIES FOR WATER, AIR AND HEAT FLOW IN THE UNSATURATED ZONE OF YUCCA MOUNTAIN, NEVADA. Office of Scientific and Technical Information (OSTI), June 1998. http://dx.doi.org/10.2172/776319.
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Russo, David, Daniel M. Tartakovsky, and Shlomo P. Neuman. Development of Predictive Tools for Contaminant Transport through Variably-Saturated Heterogeneous Composite Porous Formations. United States Department of Agriculture, December 2012. http://dx.doi.org/10.32747/2012.7592658.bard.
Full textAbstract:
The vadose (unsaturated) zone forms a major hydrologic link between the ground surface and underlying aquifers. To understand properly its role in protecting groundwater from near surface sources of contamination, one must be able to analyze quantitatively water flow and contaminant transport in variably saturated subsurface environments that are highly heterogeneous, often consisting of multiple geologic units and/or high and/or low permeability inclusions. The specific objectives of this research were: (i) to develop efficient and accurate tools for probabilistic delineation of dominant geologic features comprising the vadose zone; (ii) to develop a complementary set of data analysis tools for discerning the fractal properties of hydraulic and transport parameters of highly heterogeneous vadose zone; (iii) to develop and test the associated computational methods for probabilistic analysis of flow and transport in highly heterogeneous subsurface environments; and (iv) to apply the computational framework to design an “optimal” observation network for monitoring and forecasting the fate and migration of contaminant plumes originating from agricultural activities. During the course of the project, we modified the third objective to include additional computational method, based on the notion that the heterogeneous formation can be considered as a mixture of populations of differing spatial structures. Regarding uncertainly analysis, going beyond approaches based on mean and variance of system states, we succeeded to develop probability density function (PDF) solutions enabling one to evaluate probabilities of rare events, required for probabilistic risk assessment. In addition, we developed reduced complexity models for the probabilistic forecasting of infiltration rates in heterogeneous soils during surface runoff and/or flooding events Regarding flow and transport in variably saturated, spatially heterogeneous formations associated with fine- and coarse-textured embedded soils (FTES- and CTES-formations, respectively).We succeeded to develop first-order and numerical frameworks for flow and transport in three-dimensional (3-D), variably saturated, bimodal, heterogeneous formations, with single and dual porosity, respectively. Regarding the sampling problem defined as, how many sampling points are needed, and where to locate them spatially in the horizontal x₂x₃ plane of the field. Based on our computational framework, we succeeded to develop and demonstrate a methdology that might improve considerably our ability to describe quntitaively the response of complicated 3-D flow systems. The results of the project are of theoretical and practical importance; they provided a rigorous framework to modeling water flow and solute transport in a realistic, highly heterogeneous, composite flow system with uncertain properties under-specified by data. Specifically, they: (i) enhanced fundamental understanding of the basic mechanisms of field-scale flow and transport in near-surface geological formations under realistic flow scenarios, (ii) provided a means to assess the ability of existing flow and transport models to handle realistic flow conditions, and (iii) provided a means to assess quantitatively the threats posed to groundwater by contamination from agricultural sources.
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Warrick, Arthur, Uri Shani, Dani Or, and Muluneh Yitayew. In situ Evaluation of Unsaturated Hydraulic Properties Using Subsurface Points. United States Department of Agriculture, October 1999. http://dx.doi.org/10.32747/1999.7570566.bard.
Full textAbstract:
The primary information for accurately predicting water and solute movement and their impact on water quality is the characterization of soil hydraulic properties. This project was designed to develop methods for rapid and reliable estimates of unsaturated hydraulic properties of the soil. Particularly, in situ methodology is put forth, based on subsurface point sources. Devices were designed to allow introduction of water in subsurface settings at constant negative heads. The ability to operate at a negative head allows a direct method of finding unsaturated soil properties and a mechanism for eliminating extremely rapid preferential flow from the slow matrix flow. The project included field, laboratory and modeling components. By coupling the measurements and the modeling together, a wider range of designs can be examined, while at the same time realistic performance is assured. The developed methodology greatly expands the possibilities for evaluating hydraulic properties in place, especially for measurements in undisturbed soil within plant rooting zones. The objectives of the project were (i) To develop methods for obtaining rapid and reliable estimates of unsaturated hydraulic properties in situ, based on water distribution from subsurface point sources. These can be operated with a constant flow or at a constant head; (ii) To develop methods for distinguishing between matrix and preferential flow using cavities/permeameters under tension; (iii) To evaluate auxiliary measurements such as soil water content or tensions near the operating cavities to improve reliability of results; and (iv: To develop numerical and analytical models for obtaining soil hydraulic properties based on measurements from buried-cavity sources and the auxiliary measurements. The project began in July 1995 and was terminated in November 1998. All of the objectives were pursued. Three new subsurface point sources were designed and tested and two old types were also used. Two of the three new designs used a nylon cloth membrane (30 mm) arranged in a cylindrical geometry and operating at a negative water pressure (tension). A separate bladder arrangement allowed inflation under a positive pressure to maintain contact between the membrane and the soil cavity. The third new design used porous stainless steel (0.5 and 5 mm) arranged in six segments, each with its own water inlet, assembled to form a cylindrical supply surface when inflated in a borehole. The "old" types included an "off-the-shelf" porous cup as well as measurements from a subsurface drip emitter in a small subsurface cavity. Reasonable measurements were made with all systems. Sustained use of the cloth membrane devices were difficult because of leaks and plugging problems. All of the devices require careful consideration to assure contact with the soil system. Steady flow was established which simplified the analysis (except for the drip emitter which used a transient analysis).