Self Potential Tomographic Technique to Detect Soil Water Movements in the Vadose Zone: Laboratory Measurements.

2008 ◽  
Vol 1 (1) ◽  
pp. 137-153
Author(s):  
D. MARCHESE ◽  
G. DI BELLO ◽  
M. GRECO ◽  
V. LAPENNA ◽  
E. RIZZO ◽  
...  
Keyword(s):  
Soil Water ◽  
Vadose Zone ◽  
Laboratory Measurements ◽  
Tomographic Technique ◽  
Self Potential

Characterization of hydraulic properties in the upper vadose zone for two aquifers in Slovenia

2021 ◽  
Author(s):  
Vesna Zupanc ◽  
Matjaž Glavan ◽  
Miha Curk ◽  
Urša Pečan ◽  
Michael Stockinger ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Soil Water ◽  
Water Flow ◽  
Vadose Zone ◽  
Hydraulic Properties ◽  
Isotope Composition ◽  
Transport Processes ◽  
Precipitation Event ◽  
Water Fluxes ◽  
Flow And Transport

<p>Environmental tracers, present in the environment and provided by nature, provide integrative information about both water flow and transport. For studying water flow and solute transport, the hydrogen and oxygen isotopes are of special interest, as their ratios provide a tracer signal with every precipitation event and are seasonally distributed. In order to follow the seasonal distribution of stable isotopes in the soil water and use this information for identifying hydrological processes and hydraulic properties, soil was sampled three times in three profiles, two on Krško polje aquifer in SE Slovenia and one on Ljubljansko polje in central Slovenia. Isotope composition of soil water was measured with the water-vapor-equilibration method. Based on the isotope composition of soil water integrative information about water flow and transport processes with time and depth below ground were assessed. Porewater isotopes were in similar range as precipitation for all three profiles.  Variable isotope ratios in the upper 60 cm for the different sampling times indicated dynamic water fluxes in this upper part of the vadose zone. Results also showed more evaporation at one sampling location, Brege. The information from stable isotopes will be of importance for further analyzing the water fluxes in the vadose zone of the study sties. <br>This research was financed by the ARRS BIAT 20-21-32 and IAEA CRP 1.50.18 Multiple isotope fingerprints to identify sources and transport of agro-contaminants.  </p>

Passive Capillary Sampler for Measuring Soil Water Drainage and Flux in the Vadose Zone: Design, Performance, and Enhancement

2008 ◽  
Vol 24 (4) ◽  
pp. 439-446 ◽  
Author(s):  
J. D. Jabro ◽  
Y. Kim ◽  
R. G. Evans ◽  
W. M. Iversen ◽  
W. B. Stevens
Keyword(s):  
Soil Water ◽  
Vadose Zone ◽  
Water Drainage ◽  
Design Performance

THE USE OF ACOUSTIC LOGS IN THE EVALUATION OF SANDSTONE RESERVOIRS

Geophysics ◽  
1960 ◽  
Vol 25 (1) ◽  
pp. 250-274 ◽  
Author(s):  
G. R. Pickett
Keyword(s):  
Acoustic Velocity ◽  
Pressure Differential ◽  
Well Bore ◽  
Laboratory Measurements ◽  
Theoretical Relation ◽  
Hexagonal Packing ◽  
Empirical Relations ◽  
Borehole Logs ◽  
Acoustic Velocities ◽  
Self Potential

It is shown that acoustic velocities in sandstones are primarily dependent on porosity, shaliness, and pressure differential between overburden and fluid pressures. Although there are undoubtedly other variables which have some effect on acoustic velocities in sandstones, usable porosity predictions can be made from acoustic borehole logs if measured velocities are corrected for effects of pressure differential and shaliness. A theoretical relation between acoustic velocity and pressure differential in a hexagonal packing of spheres has been empirically extended by correlation of laboratory measurements on cores with actual well‐bore measurements. A system of empirical relations among acoustic velocity, porosity, and self potential of sandstones is developed. Further, it appears that the resistivity of water in permeable rocks can be estimated from the velocity and resistivity of adjoining shales. When this is possible, the SP log can then be used to estimate the shaliness of a sandstone in order to correct velocities for porosity estimates.

scholarly journals Self-potential investigations of a gravel bar in a restored river corridor

2011 ◽  
Vol 15 (3) ◽  
pp. 729-742 ◽  
Author(s):  
N. Linde ◽  
J. Doetsch ◽  
D. Jougnot ◽  
O. Genoni ◽  
Y. Dürst ◽  
...  
Keyword(s):  
Water Table ◽  
Vadose Zone ◽  
Time Varying ◽  
Concentration Gradients ◽  
Electrode Potentials ◽  
Source Contributions ◽  
Influence Of Water ◽  
Potential Mapping ◽  
Gravel Bar ◽  
Self Potential

Abstract. Self-potentials (SP) are sensitive to water fluxes and concentration gradients in both saturated and unsaturated geological media, but quantitative interpretations of SP field data may often be hindered by the superposition of different source contributions and time-varying electrode potentials. Self-potential mapping and close to two months of SP monitoring on a gravel bar were performed to investigate the origins of SP signals at a restored river section of the Thur River in northeastern Switzerland. The SP mapping and subsequent inversion of the data indicate that the SP sources are mainly located in the upper few meters in regions of soil cover rather than bare gravel. Wavelet analyses of the time-series indicate a strong, but non-linear influence of water table and water content variations, as well as rainfall intensity on the recorded SP signals. Modeling of the SP response with respect to an increase in the water table elevation and precipitation indicate that the distribution of soil properties in the vadose zone has a very strong influence. We conclude that the observed SP responses on the gravel bar are more complicated than previously proposed semi-empiric relationships between SP signals and hydraulic head or the thickness of the vadose zone. We suggest that future SP monitoring in restored river corridors should either focus on quantifying vadose zone processes by installing vertical profiles of closely spaced SP electrodes or by installing the electrodes within the river to avoid signals arising from vadose zone processes and time-varying electrochemical conditions in the vicinity of the electrodes.

Density-dependent calibration of multisensor capacitance probes in coarse soil

2015 ◽  
Vol 95 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Julie D. Zettl ◽  
Mingbin Huang ◽  
S. Lee Barbour ◽  
Bing C. Si
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Field Measurements ◽  
Water Dynamics ◽  
Laboratory Measurements ◽  
Calibration Equation ◽  
Density Dependent ◽  
Capacitance Probe ◽  
The Relationship ◽  
Coarse Soil

Zettl, J. D., Huang, M., Barbour, S. L. and Si, B. C. 2015. Density-dependent calibration of multisensor capacitance probes in coarse soil. Can. J. Soil Sci. 95: 331–336. Coarse-textured reconstructed soils are utilized extensively in the reclamation of mining waste. Accurate and continuous sensing of soil water content is required to understand soil water dynamics and evaluate the hydraulic characteristics of these soils. The EnviroSCAN (Sentek Pty. Ltd, Australia) is a semi-permanent multisensor capacitance probe (MCP) capable of continuous measurement of volumetric water content (θv) and has been used to monitor reclamation soil cover performance. Calibration of these probes is required to improve the accuracy of field measurements. In this study, field and laboratory measurements were undertaken over a range of water contents and bulk densities to refine the relationship between θvand scaled frequency (SF) measured by the MCP. The manufacturer's calibration equation tended to underestimate θvunder wet conditions (θv>0.35 cm3cm–3). Our experimental data showed that bulk density (ρb) did affect the MCP calibration and consequently a new calibration equation that includes the effect of ρbis developed using laboratory measurements and validated using field measurements. This equation provided the highest degree of correlation and the smallest standard deviation of prediction to measured values of θvfor laboratory and field measurements, respectively. This calibration improves the application of the EnviroSCAN for coarse-textured soils such as those utilized in this study.

scholarly journals Diurnal pattern of the drying front in the desert and its application for determining the effective infiltration

2009 ◽  
Vol 6 (1) ◽  
pp. 1021-1054 ◽  
Author(s):  
Y. Zeng ◽  
Z. Su ◽  
L. Wan ◽  
Z. Yang ◽  
T. Zhang ◽  
...  
Keyword(s):  
Soil Water ◽  
Vadose Zone ◽  
Inner Mongolia ◽  
Rainfall Event ◽  
Balance Model ◽  
Physical Parameters ◽  
Badain Jaran Desert ◽  
Hydrological Process ◽  
Diurnal Pattern ◽  
Variation Pattern

Abstract. Located in western Inner Mongolia, the Badain Jaran Desert is the second largest desert in China and consists of a regular series of stable megadunes, among which over 70 permanent lakes exist. The unexpected lakes in desert attracted research interests on exploring the hydrological process under this particular landscape; however, a very few literatures exist on the diurnal and spatial variation of the drying front in this area, which is the main issue in the desert hydrological process to characterize the movement of water in soil. In order to understand the drying front in the Badain Jaran Desert, a field campaign was conducted by the observations of soil physical parameters and micrometeorological parameters. With the field data, the performance of a vadose zone soil water balance model, the HYDRUS, was verified and calibrated. Then, the HYDRUS was used to produce the spatial and temporal information of coupled water, water vapour and heat transport in sand to characterize the variation pattern of the drying front before, during and after the rainfall. Finally, the deepest drying front was applied to determine the effective infiltration, which is defined as the amount of soil water captured by the sand beneath the deepest drying front by infiltrating water of an incident rainfall event.

scholarly journals Measuring Water Transmission Parameters in Vadose Zone Using Ponded Infiltration Techniques

2002 ◽  
Vol 7 (2) ◽  
pp. 17
Author(s):  
D.E. Elrick ◽  
W.D. Reynolds
Keyword(s):  
Soil Water ◽  
Vadose Zone ◽  
Plant Nutrient ◽  
Industrial Chemicals ◽  
Transmission Parameters ◽  
Primary Mechanism ◽  
Soil Water Flow ◽  
Constant Head ◽  
Water Transmission ◽  
Infiltration Techniques

The flow of soil water is characterized by water transmission parameters, field-saturated hydraulic conductivity, matric flux potential and sorptivity. Soil water flow is, in turn, the primary mechanism by which soil contaminants, such as excess plant nutrient, bacteria, viruses, salts, and industrial chemicals are transported. Consequently, knowledge of soil water transmission parameters is essential for understanding, preventing and remediating the contamination of soil water and ground water. This paper describes steady-state and transient methods for obtaining soil water transmission parameters from ponded infiltration under constant head and falling head conditions in surface rings and shallow auger holes. Also discussed are the conditions under which the various methods are most appropriate. 

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