scholarly journals An Analytical Solution for Non-Darcian Flow on a Constant Head Packer Test in the Interlayer Staggered Zone

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qi Shen ◽  
Zhifang Zhou ◽  
Meng Chen ◽  
Sijia Li ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Power Index ◽  
Injection Pressure ◽  
Hydraulic Head ◽  
Analytic Model ◽  
In Situ Tests ◽  
Specific Storage ◽  
Packer Test ◽  
Baihetan Hydropower Station ◽  
Constant Head

Groundwater flow in an aquifer has frequently been found to be non-Darcian by performing in situ tests. A novel analytic model is proposed in this study for describing the unsteady non-Darcian flow in a confined aquifer by taking advantage of the observed flow rate and injection pressure during the constant head packer test. A linearization approximation of the Izbash equation is used to approximate the nonlinear term in the governing equation. This analytic model is applied to describe the non-Darcian flow in the interlayer staggered zone at the Baihetan hydropower station, China. The test results inversed by the genetic algorithm show that non-Darcian flow happened during the test under the injection pressure 0.3 MPa with the power index n is 1.278, non-Darcian hydraulic conductivity k 1 is 1.613 × 10 − 5  cm/s and the specific storage S s is 9.757 × 10 − 5  m-1, respectively. The sensitivity analysis indicated that when the power index n or the specific storage S s is larger, and the hydraulic head will increase more slowly and needs longer to stabilize, but the non-Darcian hydraulic conductivity k 1 shows the opposite trend. Moreover, the hydraulic head is more sensitive to the power index n compared to other parameters at late times. The findings of this study reveal the non-Darcian flow during the constant head packer test and provide a simple and fast way to estimate parameters for more accurate seepage field simulation.

scholarly journals Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie
Keyword(s):  
Hydraulic Conductivity ◽  
Field Measurements ◽  
Natural Soil ◽  
In Situ Tests ◽  
Seepage Analysis ◽  
Soil Deposits ◽  
Seepage Modeling ◽  
Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

Effect of temperature on streambed vertical hydraulic conductivity

2013 ◽  
Vol 45 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Weihong Dong ◽  
Gengxin Ou ◽  
Xunhong Chen ◽  
Zhaowei Wang
Keyword(s):  
Hydraulic Conductivity ◽  
Water Temperature ◽  
Sediment Cores ◽  
Effect Of Temperature ◽  
In Situ Tests ◽  
Effect Of Water ◽  
Vertical Hydraulic Conductivity ◽  
Increasing Trend ◽  
Streambed Vertical Hydraulic Conductivity

In this study, in situ and on-site permeameter tests were conducted in Clear Creek, Nebraska, USA to evaluate the effect of water temperature on streambed vertical hydraulic conductivity Kv. Fifty-two sediment cores were tested. Five of them were transferred to the laboratory for a series of experiments to evaluate the effect of water temperature on Kv. Compared with in situ tests, 42 out of the 52 tests have higher Kv values for on-site tests. The distribution of water temperature at the approximately 50 cm depth of streambed along the sand bar was investigated in the field. These temperatures had values in the range 14–19 °C with an average of 16 °C and had an increasing trend along the stream flow. On average, Kv values of the streambed sediments in the laboratory tests increase by 1.8% per 1 °C increase in water temperature. The coarser sandy sediments show a greater increase extent of the Kv value per 1 °C increase in water temperature. However, there is no distinct increasing trend of Kv value for sediment containing silt and clay layers.

scholarly journals Comparison of three measurement methods of saturated hydraulic condutivity

2006 ◽  
Vol 3 (3) ◽  
pp. 987-1019 ◽  
Author(s):  
C. Fallico ◽  
E. Migliari ◽  
S. Troisi
Keyword(s):  
Hydraulic Conductivity ◽  
Measurement Method ◽  
Sandy Loam ◽  
Measurement Methods ◽  
Soil Core ◽  
Statistical Parameters ◽  
Factors Affecting ◽  
Average Value ◽  
Constant Head ◽  
Log Normal

Abstract. After pointing out the importance of the saturated hydraulic conductivity (ks) measurements and the difficulties and uncertainties that are present, and after recalling salient aspects of three well-known measurement methods of this parameter (i.e. constant-head tension infiltrometer (TI) method, constant-head pressure infiltrometer (PI) method and soil core (SC) estimates method), the results of an investigation on data which were obtained during a measurement campaign on an area of 800 m2, on a sandy loam hillslope, located in Southern Italy, were carried out again here. Three sets of values of ks, obtained with these measurement methods, were analyzed statistically, verifying that the log-normal distribution describes these better than the normal one; moreover, the more significant statistical parameters of each set were compared (average value , amplitude A, coefficient of variation CV and standard deviation SD), individualizing the more significant differences. The greatest value of hydraulic conductivity was found with method (PI), while the smallest with (SC) and the intermediate with (TI); these differences were translated into macroporosity and into the influence of the single measurement method. Moreover, referring to the possible factors affecting the results, the importance can be noted of the structure, the texture and the soil events, in terms of utilization, which can affect the measure of ks leading often to very different values even for similar soils, but with a different history, independently of the coincidence of the measurement points and they can be determining to explain the differences affecting the results obtained in analogous investigations by other researchers. Having confirmed that generalization is not possible, the need was emphasized to adopt the necessary devices relating to the specific measurement method, case by case, and to carefully explain the obtained results, in the light of the peculiarities and the limits of each situation. Finally, the results of similar statistical analysis carried out on a greater number of ks values, measured through the (TI) and (PI) methods are shown in this paper, with some statistical considerations on the increasing of the measurements number.

scholarly journals CONTROLE ESTATÍSTICO DE QUALIDADE DA CONDUTIVIDADE HIDRÁULICA EM LUVISSOLO E NEOSSOLO COM VARIAÇÃO DA DENSIDADE DO SOLO

Irriga ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 16-24
Author(s):  
Floriano Luiz Suszek ◽  
Silvio Cesar Sampaio ◽  
Vera Lucia Antunes De Lima
Keyword(s):  
Hydraulic Conductivity ◽  
Control Charts ◽  
Density Variation ◽  
Statistical Quality Control ◽  
Agricultural Drainage ◽  
Sensitivity Index ◽  
Statistical Control ◽  
Soil Physics ◽  
Constant Head ◽  
Improving Accuracy

CONTROLE ESTATÍSTICO DE QUALIDADE DA CONDUTIVIDADE HIDRÁULICA EM LUVISSOLO E NEOSSOLO COM VARIAÇÃO DA DENSIDADE DO SOLO     FLORIANO LUIZ SUSZEK1; SILVIO CÉSAR SAMPAIO2 E VERA LÚCIA ANTUNES DE LIMA3   1Doutor em Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola (PGEAGRI), Universidade Estadual do Oeste do Paraná (UNIOESTE), Rua Universitária, nº 1619 – Jd. Universitário, CEP: 85809-110, Cascavel, Paraná, Brasil, [email protected]. 2Universidade Estadual do Oeste do Paraná, Departamento de Recursos Hídricos e Saneamento Ambiental, Rua Universitária, nº 1619 – Jd. Universitário, CEP: 85809-110, Cascavel, Paraná, Brasil, [email protected]. 3Universidade Federal de Campina Grande (UFCG), Centro de Tecnologia e Recursos Naturais, Rua Aprígio Veloso, nº 882, Universitário, CEP: 58429-900, Campina Grande, Paraíba, Brasil, [email protected].     1 RESUMO   A condutividade hidráulica é um dos principais fatores para dimensionamento de sistemas de drenagem agrícola. Uma das metodologias utilizadas para a obtenção da condutividade hidráulica é o permeâmetro de carga constante. Porém a grande variação dos resultados gera necessidade de análises para melhorar a precisão destes, como o uso de gráficos de controle estatístico de qualidade. Este trabalho analisou por meio de gráficos de controle, a metodologia do permeâmetro de carga constante para dois solos diferentes na obtenção da condutividade hidráulica, variando a densidade dos solos e analisando seu índice de sensibilidade. O LUVISSOLO CRÔMICO é mais sensível à variação de densidade do solo, para a condutividade hidráulica, do que o NEOSSOLO REGOLÍTICO. Os gráficos de controle foram úteis na melhoria da precisão dos valores analisados, mostrando a variação da condutividade hidráulica e quais foram os pontos fora dos limites desejáveis.   Palavras-chave: Drenagem agrícola, propriedades físicas do solo, permeâmetro de carga constante.     SUSZEK, F. L.; SAMPAIO, S. C.; LIMA, V. L. A. de STATISTICAL QUALITY CONTROL IN HYDRAULIC CONDUCTIVITY FOR LUVISOL AND ENTISOL WITH DENSITY VARIATION     2 ABSTRACT   Hydraulic conductivity is one of the main factors for the design of agricultural drainage systems. One of the methodologies used to obtain the hydraulic conductivity is the constant head permeameter. However, the large variation of results generates the need for analyzes to improve their accuracy, such as the use of quality statistical control graphs. This work analyzed, by means of control charts, the methodology of constant head permeameter for two different soils in obtaining hydraulic conductivity, varying the density of soils and analyzing their sensitivity index. Luvisol is more sensitive to density variation, for hydraulic conductivity, than  entisol. Control graphs were useful in improving  accuracy of the analyzed values, showing the variation of hydraulic conductivity and what were the points outside the desirable limits.   Keywords: Agricultural drainage, soil physics properties, constant head permeameter.

scholarly journals An approach to identify soil types by using hydraulic conductivity values

2018 ◽  
Vol 2 (1) ◽  
pp. 43-51
Author(s):  
Maritha Nilam Kusuma ◽  
Wahyono Hadi ◽  
Budisantoso Wirjodirdjo ◽  
Yulfiah Yulfiah
Keyword(s):  
Water Treatment ◽  
Hydraulic Conductivity ◽  
Preliminary Analysis ◽  
Soil Types ◽  
Main Role ◽  
Important Indicator ◽  
Pre Treatment ◽  
Constant Head ◽  
Soil Filtration

Water treatment in Indonesia still uses coagulant to reduce the contaminant. Therefore, an infiltration gallery is required as the pre-treatment before conventional water treatment conducted. Infiltration gallery is a natural technology for absorbing or filtrating the contaminant. The hydraulic conductivity plays the main role in soil filtration. There are many types of soil with different hydraulic conductivities. In infiltration gallery method it is important to identify the hydraulic conductivity value as the preliminary analysis because it is the important indicator to show the ability of soil to flow the water from one side to other sides when filtrating the contaminant. The slower the conductivity is, the better the quality of the water will be. The method used in this study was the Constant head Permeameter. The result of this study shows that the same type of soil type has different hydraulic conductivities.

Measuring unsaturated hydraulic conductivity (K(ψm)) of the F and H soil organic layers at small matric potential (ψm)

2011 ◽  
Vol 91 (6) ◽  
pp. 965-968
Author(s):  
B. Wilske ◽  
E. A. Johnson
Keyword(s):  
Hydraulic Conductivity ◽  
Large Data ◽  
Cold Climate ◽  
Organic Layer ◽  
Matric Potential ◽  
Large Variability ◽  
Organic Layers ◽  
Soil Organic Layer ◽  
Unsaturated Hydraulic Conductivity ◽  
Constant Head

Wilske, B. and Johnson, E. A. 2011. Measuring unsaturated hydraulic conductivity (K(ψm)) of the F and H soil organic layers at small matric potential (ψm). Can. J. Soil Sci. 91: 965–968. K(ψm) of the soil organic layers is a key parameter to assess water redistribution in cold-climate forests. This study tested the twin suction disc apparatus (TSD) as a new method to measure K(ψm) of the F and H layers directly. We compared the results to two studies. One represents a large data base, the other used similar sample locations; but both derived K(ψm) from combining two methods, i.e., pressure plate measurements combined with the instantaneous profile technique or the constant head approach. The TSD data are consistent with previous results considering the large variability in K(ψm) from the combined methods. This suggests that the TSD method represents an alternative to determine K(ψm) of the soil organic layer.

Hydraulic tomography using joint inversion of head and flux data 

2021 ◽  
Author(s):  
Behzad Pouladiborj ◽  
Olivier Bour ◽  
Niklas Linde ◽  
Laurent Longuevergne
Keyword(s):  
Hydraulic Conductivity ◽  
Joint Inversion ◽  
Data Type ◽  
Data Types ◽  
Hydraulic Tomography ◽  
Flux Data ◽  
Planning And Design ◽  
Constant Rate ◽  
Resolution Analysis ◽  
Constant Head

<p>Hydraulic tomography is a state of the art method for inferring hydraulic conductivity fields using head data. Here, a numerical model is used to simulate a steady-state hydraulic tomography experiment by assuming a Gaussian hydraulic conductivity field (also constant storativity) and generating the head and flux data in different observation points. We employed geostatistical inversion using head and flux data individually and jointly to better understand the relative merits of each data type. For the typical case of a small number of observation points, we find that flux data provide a better resolved hydraulic conductivity field compared to head data when considering data with similar signal-to-noise ratios. In the case of a high number of observation points, we find the estimated fields to be of similar quality regardless of the data type. A resolution analysis for a small number of observations reveals that head data averages over a broader region than flux data, and flux data can better resolve the hydraulic conductivity field than head data. The inversions' performance depends on borehole boundary conditions, with the best performing setting for flux data and head data are constant head and constant rate, respectively. However, the joint inversion results of both data types are insensitive to the borehole boundary type. Considering the same number of observations, the joint inversion of head and flux data does not offer advantages over individual inversions. By increasing the hydraulic conductivity field variance, we find that the resulting increased non-linearity makes it more challenging to recover high-quality estimates of the reference hydraulic conductivity field. Our findings would be useful for future planning and design of hydraulic tomography tests comprising the flux and head data.</p>

scholarly journals Approximate analysis of three-dimensional groundwater flow toward a radial collector well in a finite-extent unconfined aquifer

2016 ◽  
Vol 20 (1) ◽  
pp. 55-71 ◽  
Author(s):  
C.-S. Huang ◽  
J.-J. Chen ◽  
H.-D. Yeh
Keyword(s):  
Groundwater Flow ◽  
Integral Transform ◽  
Three Dimensional ◽  
Vertical Component ◽  
Hydraulic Head ◽  
Unconfined Aquifer ◽  
Specific Yield ◽  
Specific Storage ◽  
Sink Term ◽  
Radial Collector Well

Abstract. This study develops a three-dimensional (3-D) mathematical model for describing transient hydraulic head distributions due to pumping at a radial collector well (RCW) in a rectangular confined or unconfined aquifer bounded by two parallel streams and no-flow boundaries. The streams with low-permeability streambeds fully penetrate the aquifer. The governing equation with a point-sink term is employed. A first-order free surface equation delineating the water table decline induced by the well is considered. Robin boundary conditions are adopted to describe fluxes across the streambeds. The head solution for the point sink is derived by applying the methods of finite integral transform and Laplace transform. The head solution for a RCW is obtained by integrating the point-sink solution along the laterals of the RCW and then dividing the integration result by the sum of lateral lengths. On the basis of Darcy's law and head distributions along the streams, the solution for the stream depletion rate (SDR) can also be developed. With the aid of the head and SDR solutions, the sensitivity analysis can then be performed to explore the response of the hydraulic head to the change in a specific parameter such as the horizontal and vertical hydraulic conductivities, streambed permeability, specific storage, specific yield, lateral length, and well depth. Spatial head distributions subject to the anisotropy of aquifer hydraulic conductivities are analyzed. A quantitative criterion is provided to identify whether groundwater flow at a specific region is 3-D or 2-D without the vertical component. In addition, another criterion is also given to allow for the neglect of vertical flow effect on SDR. Conventional 2-D flow models can be used to provide accurate head and SDR predictions if satisfying these two criteria.

Effects of skidding on forest soil infiltration in west-central Alberta

2000 ◽  
Vol 80 (4) ◽  
pp. 617-624 ◽  
Author(s):  
A. D. Startsev ◽  
D. H. McNabb
Keyword(s):  
Hydraulic Conductivity ◽  
Boreal Forests ◽  
Soil Water Potential ◽  
Infiltration Rate ◽  
Forest Harvesting ◽  
Saturated Hydraulic Conductivity ◽  
Soil Freezing ◽  
Surface Erosion ◽  
Soil Infiltration ◽  
Constant Head

Soil compaction during forest harvesting generally reduces macropore space, which reduces infiltration and increases the potential for surface erosion and waterlogging. Hydrological effects of 3, 7 and 12 skidding cycles and their persistence were evaluated for 3 yr at 14 sites, which represented a range of soil texture and compaction conditions in the foothills and boreal forests of Alberta. Saturated hydraulic conductivity (HC) was determined using a constant head method on soil cores collected from 5- and 10-cm depths; unconfined infiltration rate of the surface soil (IR) was measured in situ with tension infiltrometers at near saturation. A significant (P < 0.05) increase in bulk density during skidding caused a significant reduction in both HC and IR after the first three cycles at eight sites where soil water potential at the time of skidding was higher than −15 kPa; the decrease at the other sites was not significant. Additional traffic, up to 12 cycles, did not cause a further significant decrease in HC or IR. The infiltration rate of soil compacted by three skidding cycles showed a recovery trend. However, in more intensively trafficked soils, compaction effects on infiltration remained significant for at least 3 yr, which was possibly attributed to heavy snowpacks preventing soil freezing at lower depths. Key words: Saturated hydraulic conductivity, unconfined infiltration rate, tension infiltrometers, skidders, boreal forest, Alberta

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