Comparison of Field and Laboratory Methods for Measuring Hydraulic Conductivity in the Unsaturated Zone in Engineered and Native Soils

2017 ◽  
Author(s):  
Pablo R. Garza ◽  
Zachary Zukowski ◽  
Andrea Welker ◽  
Derron LaBrake ◽  
Richard Nalbandia
Keyword(s):  
Hydraulic Conductivity ◽  
Unsaturated Zone ◽  
Laboratory Methods ◽  
Native Soils

scholarly journals The Dynamics of Sea Tide-Induced Fluctuations of Groundwater Level and Freshwater-Saltwater Interface in Coastal Aquifers: Laboratory Experiments and Numerical Modeling

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Elad Levanon ◽  
Haim Gvirtzman ◽  
Yoseph Yechieli ◽  
Imri Oz ◽  
Elad Ben-Zur ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Groundwater Level ◽  
Coastal Aquifer ◽  
Unsaturated Zone ◽  
Laboratory Experiments ◽  
Time Lag ◽  
Time Lags ◽  
Saturation Degree ◽  
Aquifer Systems ◽  
Capillary Zone

Laboratory experiments were conducted in a vertical, two-dimensional, rectangular flow tank, simulating the response of a phreatic coastal aquifer to a sea tide. Imposed sinusoidal fluctuations of the saltwater level at one side of the flow tank caused three types of fluctuations: (a) hydraulic head throughout the aquifer, (b) saturation degree within the capillary fringe, and (c) salt concentration surrounding the freshwater-saltwater interface (FSI), all recorded by head, saturation, and salinity sensors, respectively. Significant time lags were observed both in the saturation degree within the unsaturated zone and in the salinity within the FSI. All measured values, recorded by the three types of sensors, were simulated and reproduced using a numerical model. The calibrated model was used for mapping the time lags throughout the aquifer. It was found that the time lag of saturation fluctuations within the unsaturated zone increased upward from the groundwater level as the unsaturated hydraulic conductivity decreased. Similarly, the time lag of salinity fluctuations within the FSI increased downward, with distance from the groundwater level. We interpret the low hydraulic conductivity at the capillary zone as the source of attenuation of both saturation and salinity, because both are controlled by the vertical advection of the whole freshwater body. This advection is significantly slower compared to the dynamics of pressure diffusion. The uniqueness of this study is that it provides quantitative data on the attenuation at the capillary zone and its effect on the salinity time lag in coastal aquifer systems.

scholarly journals Characterization of the field saturated hydraulic conductivity on a hillslope: measurement techniques, data sensitivity analysis and spatial correlation modelling

2005 ◽  
Vol 2 (4) ◽  
pp. 1247-1298 ◽  
Author(s):  
C. Fallico ◽  
E. Migliari ◽  
S. Troisi
Keyword(s):  
Sensitivity Analysis ◽  
Hydraulic Conductivity ◽  
Spatial Correlation ◽  
Unsaturated Zone ◽  
Measurement Errors ◽  
Measurement Techniques ◽  
Saturated Hydraulic Conductivity ◽  
Spatial Correlation Structure ◽  
Disc Infiltrometer ◽  
Data Sensitivity

Abstract. In the context of studies aiming at the estimation of effective parameters for unsaturated zone modelling, this work tackles the problem of experimental data quality, considering the large collection of data gathered at an experimental site equipped for unsaturated zone hydraulic monitoring in the alluvial basin of a Calabrian river, in the South of Italy. Focusing attention on field saturated hydraulic conductivity, the in-site measurement techniques by tension disc and pressure ring infiltrometers are considered, pointing out the main indications for the correct use of each measuring approach; laboratory techniques are also considered. Statistical data analysis showed that the measurements performed by tension disc infiltrometer supplied values of hydraulic conductivity which are on average lower and more homogeneous than the values provided by the other measurement techniques considered. Sensitivity analysis was then carried out by Monte Carlo simulation on the parameter sampling achieved by field measurement techniques in order to evaluate the influence of any possible small measurement errors on the data. Sensitivity analysis showed that both ring and disc infiltrometer are tools reliable enough for the in situ measurements of field saturated hydraulic conductivity. Finally, after a data merging procedure giving origin to different sets of data, the spatial correlation structure of field saturated hydraulic conductivity is investigated, using well-known geostatistical techniques.

Experimental Investigation of Soil and Ground Water Impacts Caused by Vinasse Disposal

1991 ◽  
Vol 24 (11) ◽  
pp. 77-85 ◽  
Author(s):  
R. L. Cruz ◽  
A. M. Righetto ◽  
M. A. Nogueira
Keyword(s):  
Experimental Investigation ◽  
Organic Matter ◽  
Hydraulic Conductivity ◽  
Unsaturated Zone ◽  
Water Retention ◽  
Nitrate Concentration ◽  
Chemical Analyses ◽  
Nitrogen Absorption ◽  
Soil Water Retention ◽  
Alcohol Production

The problems caused by the residual effluents of wine distilleries for alcohol production are well known. The effluent effects in soil and groundwater are being researched in an area with sugar cane culture which receives; yearly, vinasse by dispersion. Samples are being collected from the soil, the groundwater and the existing creeks in the area Four sub-areas are being monitored separately with a vinasse application of 300 m3/ha year. Experimentation periods in each area have been 0, 5, 10 and 15 years. In the unsaturated zone, samples are being collected at depths of 25, 75 and 150 cm. The chemical analyses include macro and micro nutrients, organic matter and pH. Physical analyses give the soil water retention, hydraulic conductivity and soil particle distribuition. These measurements permit the evatution of nitrogen absorption and fertility changes of the soil. A tendency for the maintenance of soil fertility can be observed but with an elevation of nitrate concentration in groundwater.

scholarly journals VARIABILIDADE ESPACIAL DA CONDUTIVIDADE HIDRÁULICA DO SOLO SATURADO EM LATOSSOLO AMARELO DISTROCOESO, NO MUNICÍPIO DE CRUZ DAS ALMAS

Irriga ◽  
2018 ◽  
Vol 22 (2) ◽  
pp. 259-274 ◽  
Author(s):  
Karla Silva Santos Alvares de Almeida ◽  
Luciano Da Silva Souza ◽  
Vital Pedro Da Silva Paz ◽  
Fagner Taiano Dos Santos Silva ◽  
Davi Ney Santos ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Bulk Density ◽  
Spatial Dependence ◽  
Total Porosity ◽  
Soil Bulk Density ◽  
Constant Load ◽  
Saturated Hydraulic Conductivity ◽  
Laboratory Methods ◽  
Normality Test ◽  
E Mail

VARIABILIDADE ESPACIAL DA CONDUTIVIDADE HIDRÁULICA DO SOLO SATURADO EM LATOSSOLO AMARELO DISTROCOESO, NO MUNICÍPIO DE CRUZ DAS ALMAS  KARLA SILVA SANTOS ALVARES DE ALMEIDA1; LUCIANO DA SILVA SOUZA1; VITAL PEDRO DA SILVA PAZ1; FAGNER TAIANO DOS SANTOS SILVA2; DAVI NEY SANTOS1 E JULIANA DA SILVA LOPES PEREIRA1 1Universidade Federal do Recôncavo da Bahia – UFRB, Rua Rui Barbosa, 710 – Campus Universitário – CEP 44380-000 – Cruz das Almas – BA, e-mail: [email protected]; [email protected]; [email protected]; [email protected]; [email protected] do Estado de Santa Catarina – UDESC, Centro de Ciências Agroveterinárias – CAV, Av. Luiz de Camões, 2090 – CEP 88520-000 -  Lages – SC, e-mail: [email protected]  1 RESUMO O objetivo desse trabalho foi caracterizar a variabilidade espacial da condutividade hidráulica do solo saturado (K0) utilizando dois métodos de laboratório e amostras com diferentes volumes em Latossolo Amarelo Distrocoeso localizado no Município de Cruz das Almas. Foram coletadas amostras com estrutura indeformada em dois tipos de anéis volumétricos com 0,081 m de altura e 0,070 m de diâmetro (≈312 cm3) e com 0,05 m de altura e de diâmetro (98 cm3). Nos mesmos pontos de amostragem da K0 foram coletadas amostras deformadas para quantificação de areia, silte, argila, porosidade total, macro e microporosidade, densidade do solo em uma malha amostral de 7 x 7 pontos espaçados em 2,0 x 2,0 m, totalizando uma área de 196,0 m². Os resultados foram submetidos à análise estatística exploratória e teste de normalidade de Shapiro-Wilk; posteriormente, verificou-se a dependência espacial pela análise geoestatística. Os resultados revelaram que para a profundidade de 0-0,15 m a condutividade hidráulica determinada no permeâmetro de carga constante no cilindro de volume maior apresentou menor coeficiente de variação, indicando uma melhor representatividade das amostras; a densidade do solo apresentou índice de dependência espacial moderada, com alcance de 1,22 m e semivariograma tipo esférico para a profundidade de 0-0,15m; para a profundidade de 0,15-0,30 o índice de dependência espacial foi forte, com alcance de 1,54 m e semivariograma tipo exponencial. Palavras-chave: condutividade hidráulica saturada, Tabuleiro Costeiro, geoestatística.  ALMEIDA, K. S. S. A.; SOUZA, L. S.; PAZ, V. P. S.; SILVA, F. T. S.; SANTOS, D. N.; PEREIRA, J. S. L.SPATIAL VARIABILITY OF HYDRAULIC CONDUCTIVITY OF SATURATED SOIL USING TWO LABORATORY METHODS AND SAMPLES WITH DIFFERENTS VOLUMES     2 ABSTRACT The objective of this work was to characterize the spatial variability of saturated hydraulic conductivity (K0) using two laboratory methods and samples with different volumes in Oxisoil Distrocoeso located in the city of Cruz das Almas. Deformed structural samples were collected in two types of volumetric rings with 0.081 m long and 0.070 m in diameter (312 cm3) and 0.05 m in height and diameter (98 cm3). In the same sampling points of K0 deformed samples were collected for quantification of sand, silt, clay, total porosity, macro and microporosity, bulk density in a sample grid of 7 x 7 points spaced at 2.0 x 2.0 m totaling an area of 196.0 m². The results were submitted to exploratory statistical analysis  and Shapiro-Wilk normality test; later, the spatial dependence was verified by geostatistical analysis. The results showed that for the depth of 0-0.15 m the hydraulic conductivity determined in the constant load permeameter in the higest volume  cylinder showed a lower coefficient of variation, indicating a better representativeness of the samples; soil bulk density showed moderate spatial dependence index, with a range of 1.22 m and pherical-type semivariogram to the depth of 0-0.15m; to the depth of 0.15-0.30 the spatial dependence index was strong, reaching 1.54 m and exponential semivariogram. Keywords: Saturated hydraulic conductivity, coastal plain, geostatistics

Sign in / Sign up

Export Citation Format

Share Document