scholarly journals MODELO APLICADO AO DIMENSIONAMENTO DE DRENOS SUBTERRÂNEOS PARA ÉPOCA DA IRRIGAÇÃO

Irriga ◽  
2015 ◽  
Vol 1 (2) ◽  
pp. 109-120 ◽  
Author(s):  
Marinaldo Ferreira Pinto ◽  
Dinara Grasiela Alves ◽  
Conan Ayade Salvador
Keyword(s):  
Hydraulic Conductivity ◽  
Water Table ◽  
Rio De Janeiro ◽  
Irrigation Period ◽  
Period 2 ◽  
Proposed Model ◽  
Alternative Methodology ◽  
Impermeable Layer ◽  
E Mail

MODELO APLICADO AO DIMENSIONAMENTO DE DRENOS SUBTERRÂNEOS PARA ÉPOCA DA IRRIGAÇÃO  MARINALDO FERREIRA PINTO1; DINARA GRASIELA ALVES2 E CONAN AYADE SALVADOR1 1 Professor Adjunto, Departamento de Engenharia, Universidade Federal Rural do Rio de Janeiro - UFRRJ. Seropédica – RJ, e-mail: [email protected]; [email protected] Pós-Doutoranda, Departamento de Engenharia, Universidade Federal Rural do Rio de Janeiro - UFRRJ. Seropédica – RJ, e-mail: [email protected]  1 RESUMO A metodologia para o dimensionamento de drenos subterrâneos para a época das irrigações é laboriosa, requerendo muitas iterações. Sendo assim, o objetivo do trabalho foi desenvolver uma metodologia alternativa para tal finalidade, baseada na equação de Glover-Dumm. Comparou-se o espaçamento entre os drenos calculado pelo método proposto e pelo método da simulação da altura do lençol freático após cada irrigação, obtendo-se o seu desempenho. Foram testados cenários com valores de condutividade hidráulica variando de 0,2 a 3,0 m d-1; camada impermeável variando de 0 a 6 m abaixo da superfície do solo; e, altura do lençol freático de 0,4 e 0,8 m sobre os drenos que proporciona a profundidade exigida pela cultura. Verificou-se que a faixa na qual o modelo proposto pode ser empregado depende da combinação das variáveis consideradas nas simulações, devendo ser analisada para cada caso. A metodologia proposta apresentou resultados semelhantes àqueles quando se utilizou a metodologia de simulação da altura do lençol freático, sendo que número de iteração para obtenção do resultado é infinitamente menor. De acordo com os resultados obtidos, pode-se concluir que o modelo desenvolvido apresentou confiabilidade quando se respeita as suas restrições. Palavras-chave: Drenagem subterrânea, Glover-Dumm, lâmina de lixiviação  PINTO, M. F.; ALVES, D. G.; SALVADOR, C. A.MODEL FOR DRAINS DESIGN TO IRRIGATION PERIOD  2 ABSTRACT The methodology for design of underground drains for irrigation period is very laborious and it requires much iteration. The objective was to develop an alternative methodology for this purpose, based on the Glover-Dumm equation. It compared the spacing between drains calculated by the proposed method and the method of simulation of the height water table after each irrigation obtaining its performance. Scenarios were tested with hydraulic conductivity values ranging from 0.2 to 3.0 m d-1; impermeable layer ranging from 0 to 6 m; and, height of the water table of 0.4 and 0.8 m that provides the required depth by culture. It verified that range at which the proposed model can be use depends on the combination of the variables considered in the simulations and must be analyzed in each case. The model showed results similar to those when using the methodology of the water table height. The number of iteration to obtain the result is infinitely less. According to the results, it can be concluded that the developed model presented reliability when it concerns their restrictions. Keywords: Drainage, Glover-Dumm, leaching depth

EFFECT OF SPATIAL VARIABILITY IN HYDRAULIC CONDUCTIVITY ON WATER TABLE DRAWDOWN

1997 ◽  
Vol 40 (2) ◽  
pp. 371-375
Author(s):  
S. O. Prasher ◽  
M. Singh ◽  
A. K. Maheshwari ◽  
R. S. Clemente
Keyword(s):  
Hydraulic Conductivity ◽  
Spatial Variability ◽  
Water Table

scholarly journals Spatial regression methods to evaluate beekeeping production in the state of Rio de Janeiro

2013 ◽  
Vol 65 (2) ◽  
pp. 553-558
Author(s):  
W.S. Tassinari ◽  
M.C. Lorenzon ◽  
E.L. Peixoto
Keyword(s):  
Rio De Janeiro ◽  
High Performance ◽  
Spatial Regression ◽  
The State ◽  
Spatial Effects ◽  
Regression Methods ◽  
Honey Production ◽  
Production Factors ◽  
Proposed Model ◽  
Wild Vegetation

Brazilian beekeeping has been developed from the africanization of the honeybees and its high performance launches Brazil as one of the world´s largest honey producer. The Southeastern region has an expressive position in this market (45%), but the state of Rio de Janeiro is the smallest producer, despite presenting large areas of wild vegetation for honey production. In order to analyze the honey productivity in the state of Rio de Janeiro, this research used classic and spatial regression approaches. The data used in this study comprised the responses regarding beekeeping from 1418 beekeepers distributed throughout 72 counties of this state. The best statistical fit was a semiparametric spatial model. The proposed model could be used to estimate the annual honey yield per hive in regions and to detect production factors more related to beekeeping. Honey productivity was associated with the number of hives, wild swarm collection and losses in the apiaries. This paper highlights that the beekeeping sector needs support and help to elucidate the problems plaguing beekeepers, and the inclusion of spatial effects in the regression models is a useful tool in geographical data.

scholarly journals Large-scale lateral saturated soil hydraulic conductivity as metric for the connectivity of the subsurface flow paths at hillslope scale

2021 ◽  
Author(s):  
Mario Pirastru ◽  
Massimo Iovino ◽  
Hassan Awada ◽  
Roberto Marrosu ◽  
Simone Di Prima ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Spatial Scale ◽  
Water Table ◽  
Subsurface Flow ◽  
Lateral Flow ◽  
Saturated Soil ◽  
Flow Paths ◽  
Soil Hydraulic Conductivity ◽  
Hillslope Scale

Lateral saturated soil hydraulic conductivity, Ks,l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes both at the hillslope and catchment scales. Likewise, the hydrological connectivity of lateral flow paths plays a significant role in determining the intensity of the subsurface flow at various spatial scales. The objective of the study is to investigate the relationship between Ks,l and hydraulic connectivity at the hillslope spatial scale. Ks,l was determined by the subsurface flow rates intercepted by drains, and by water table depths observed in a well network. Hydraulic connectivity of the lateral flow paths was evaluated by the synchronicity among piezometric peaks, and between the latter and the peaks of drained flow. Soil moisture and precipitation data were used to investigate the influence of the transient hydrological soil condition on connectivity and Ks,l. It was found that the higher was the synchronicity of the water table response between wells, the lower was the time lag between the peaks of water levels and those of the drained subsurface flow. Moreover, the most synchronic water table rises determined the highest drainage rates. The relationships between Ks,l and water table depths were highly non-linear, with a sharp increase of the values for water table levels close to the soil surface. Estimated Ks,l values for the full saturated soil were in the order of thousands of mm h-1, suggesting the activation of macropores in the root zone. The Ks,l values determined at the peak of the drainage events were correlated with the indicators of synchronicity. The sum of the antecedent soil moisture and of the precipitation was correlated with the indicators of connectivity and with Ks,l. We suggest that, for simulating realistic processes at the hillslope scale, the hydraulic connectivity could be implicitly considered in hydrological modelling through an evaluation of Ks,l at the same spatial scale.

scholarly journals An Estimation Model for Hydraulic Conductivity of Low-Permeability and Unfilled Fractured Granite in Underground Water-Sealed Storage Caverns

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yangbing Cao ◽  
Weiguo Gong ◽  
Xiangxiang Zhang ◽  
Junxi Chen ◽  
Zhenping Huang
Keyword(s):  
Hydraulic Conductivity ◽  
Water Pressure ◽  
Underground Structure ◽  
Underground Water ◽  
Stress Index ◽  
Low Permeability ◽  
Proposed Model ◽  
Imaging Results ◽  
Water Conduction ◽  
Fractured Granite

The permeability of rock mass is closely related to the stability and safety of underground structure, especially in underground water-sealed storage caverns. With regard to the estimation approaches in predicting the hydraulic conductivity of fractured granite in water-sealed storage caverns, there are some limitations of parameter selection leading to poor applicability. Focusing on the contribution of the water conduction fractures (WCF) to the hydraulic conductivity, we attempted to propose a novel model, the CA model, for estimating its hydraulic conductivity based on the fracture orientation index and the normal stress index by analyzing the borehole wall imaging results and borehole water-pressure test results in the site of underground water-sealed storage caverns. The results indicated that the proposed model is suitable for low-permeability and unfilled fractured granite, exhibiting good effectiveness by clarifying the relation between geomechanical parameters and hydraulic behavior. Further, the parameters upon which the proposed model is based are representative and easy to obtain, which has certain guiding significance and reference value for analyzing the permeability characteristics of similar rock masses.

Distribution, origin, and hydraulic influence of fractures in a clay-rich glacial deposit

1995 ◽  
Vol 32 (6) ◽  
pp. 957-975 ◽  
Author(s):  
L.D. McKay ◽  
J. Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
Groundwater Flow ◽  
Key Words ◽  
Water Table ◽  
Stress Relief ◽  
Fracture Density ◽  
Lacustrine Environment ◽  
Tritium Content ◽  
Glacial Deposit ◽  
A Site

In the unconsolidated clay-rich glacial deposits underlying a site in southwestern Ontario, fractures and root casts greatly influence hydraulic conductivity and groundwater flow. The fractures are predominantly vertical and have visible oxidation staining from surface to a depth of 6 m. Root casts commonly occur along fracture surfaces in the upper 3 m, but can also occur as holes in apparently unfractured blocks. The fractures are believed caused mainly by dessication during past periods of low water table. This hypothesis is supported by a decrease in fracture density with depth and the presence of a stiff crust, presumably caused by desiccation-induced consolidation. The random pebble fabric and faint layering indicate deposition in a calm lacustrine environment, which precludes the possibility of the fractures having been caused by overriding ice. Fractures were found below the depth of oxidation staining (6 m) but most of these appear to have been caused by stress-relief due to the excavation and subsequent drying. In the upper 3 m the fractures and root casts are responsible for field-measured hydraulic conductivity values that are up to 3 orders of magnitude greater than measured in the laboratory for samples of the unfractured matrix. High values of field-measured hydraulic conductivity, seasonal head variations greater than 0.5 m, and high tritium content all persist below the depth of root casts, indicating that hydraulically conductive fractures do exist to depths of at least 6 m and possibly as great as 12–15 m, which is well below the depth of oxidation staining. However, there is some uncertainty in this assessment of the extent of hydraulically conductive fractures because of the sensitivity to small leaks in the piezometer installations. Key words : clay, glacial, fractures, desiccation, hydraulic conductivity.

Low-Flow Hydraulic Conductivity Tests at Wells that Cross the Water Table

Ground Water ◽  
2010 ◽  
Vol 49 (3) ◽  
pp. 426-431 ◽  
Author(s):  
Alejandra T. Aragon-Jose ◽  
Gary A. Robbins
Keyword(s):  
Hydraulic Conductivity ◽  
Water Table ◽  
Low Flow

scholarly journals COMMISSION 42: CLOSE BINARIES

2010 ◽  
Vol 6 (T27B) ◽  
pp. 211-212
Author(s):  
Slavek M. Rucinski ◽  
Ignasi Ribas ◽  
Alvaro Giménez ◽  
Petr Harmanec ◽  
Ronald W. Hilditch ◽  
...  
Keyword(s):  
Rio De Janeiro ◽  
Vice President ◽  
Close Binaries ◽  
General Assembly ◽  
Past President ◽  
The Past ◽  
E Mail

During the commission business session, the past President presented the new Organizing Committee which was selected by the OC through a e-mail vote conducted during the months before the Rio de Janeiro General Assembly. The new OC will consist of Ignasi Ribas (President), Mercedes Richards (Vice President), and Slavek Rucinski (Past President) with the members: David Bradstreet, Petr Harmanec, Janusz Kaluzny, Joanna Mikolajewska, Ulisse Munari, Panos Niarchos, Katalin Olah, Theo Pribulla, Colin Scarfe and Guillermo Torres.

scholarly journals DRAINAGE OF AN IRRIGATED SALINE SOIL IN ALBERTA

1982 ◽  
Vol 62 (2) ◽  
pp. 387-396
Author(s):  
D. R. BENNETT ◽  
G. R. WEBSTER ◽  
B. A. PATERSON ◽  
D. B. HARKER
Keyword(s):  
Water Table ◽  
Crop Production ◽  
Saline Soil ◽  
Soil Depth ◽  
Drainage System ◽  
High Water ◽  
Coarse Sand ◽  
Irrigation Period ◽  
Dilution Effects ◽  
Sand And Gravel

A shallow subsurface drainage system effectively controlled a high water table and reduced salinity in an irrigated soil near Magrath, Alberta. Plastic corrugated tubing was installed in 1976 at depths of 1.1–1.5 m and spacings of 15 and 30 m in a moderately saline soil. During the irrigation period, the water table rose to within 0.3 m of the surface but was lowered to pre-irrigation levels within 48 h. The water table was maintained at, or below, the depth of the drains between irrigations. The 15- and 30-m spacings of the drain lines were equally effective in providing water table control in this lacustrine soil which was underlain by a coarse sand and gravel layer. Salinity levels were decreased substantially only within the surface 0.3-m soil depth. Quality of the drainage effluent remained constant throughout the growing season with only small dilution effects detected during irrigations. Barley yields increased to 3900 kg/ha in 1978, 2 yr following drainage of this saline soil which had been out of crop production for 20 yr.

scholarly journals Water Phase Inclination Theory for Hydraulic Conductivity Determination of Vadose Zones in Shallow Water Table Systems

2021 ◽  
Vol 54 (2B) ◽  
pp. 85-100
Author(s):  
Arkan Radi Ali
Keyword(s):  
Hydraulic Conductivity ◽  
Shallow Water ◽  
Linear Relationship ◽  
Water Table ◽  
Correlation Factor ◽  
Water Phase ◽  
Shallow Water Table ◽  
Allowable Limit ◽  
Undisturbed Soil

Water Phase Inclination is an innovative theory for hydraulic conductivity and determination of vadose zone overlying shallow water table systems. It was originated and analytically derived from Darcy's Law and based on some physio-mechanical properties of soil. Al-Musayab area of 176 Km2 at Mesopotamian region, mid-Iraq was undertaken as a case study. It consists of unconsolidated quaternary deposits and is usually finer-grained than the underlying pebbly sandstone with Mediterranean weather. The Experimental part was divided into field tests which include double ring infiltrometer tests, water table depth measurements and sampling of 32 undisturbed soil samples of surface layers scattered over the study area Whereas lab tests include; the falling and constant head permeability, grain size distribution (sieve and hydrometer analysis), soil specific gravity, direct shear tests and the measuring of Water Phase Inclinations. Angle \emptyset a glassy infiltration box is an experimental device that was manufactured to measure the Water Phase Inclination angle and aquifer simulation. It is found a generalized linear relationship between  and the angle of internal friction which is valid for   23.37 with correlation factor R² = 0.99 and both angles depend on soil texture. The k values estimated by WPI theory and that measured by traditional techniques offer a linear relationship with acceptable Root Mean Square Error equals 0.0642 < 0.1 the max allowable limit and correlation factor R² = 0.96, pointing out to the reliability and stability of the Water Phase Inclination results.

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