Use of Gamma Rays in Measuring Water Content and Permeability in Unsaturated Columns of Soil

Gurr, C. G.

doi:10.1097/00010694-196210000-00006

Cited by 63 publications

(17 citation statements)

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“…Alternatively, many direct methods are available, such those that make use of electrical resistivity (Umeda, 1969), neutron moderation (Falleiros et al, 1993), gamma ray densitometry (Gurr, 1962) and dielectric capacitance (Uno, 1970;Topp et al, 1990). Some of the dielectric-based methods which use empirically calibrated relationships between volumetric water content and sensor output signal include time domain re‰ectometry (Nissen et al, 1998), amplitude domain re‰ectometry (Nakajima et al, 1998) and frequency domain re‰ecto-metry (Lukangu et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

Measurement of Degree of Saturation on Model Ground by Digital Image Processing

Yoshimoto

Orense

Tanabe

et al. 2011

Soils and Foundations

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The degree of saturation of ground is conventionally measured at discrete points using transducers, soil moisture sensors, etc. In this paper, a novel method was developed to directly measure the degree of saturation of continuous region of ground by noting the variation in color of the ground as the amount of moisture in the soil changes. In this research, a series of experiments was conducted for the purpose of developing a method to measure the degree of saturation of ground by digital image processing. From photo images taken at various soil moisture contents, the colors of the images were converted into numerical values which were then related to known degrees of saturation. The results of the experiments showed that a method to measure the degree of saturation of ground by image processing was possible. The relation between degree of saturation and luminance value can be expressed in terms of second degree function. Good results were obtained for two soil samples with diŠerent colors and grain size distributions. The margin of error was in the order of ±5z. The method was validated through vertical seepage tests, where good agreements were obtained between the measured degrees of saturation by tensiometers and those estimated from the proposed method. The method illustrates the possibility of measuring the degree of saturation of a larger portion of the ground, which is di‹cult to perform using conventional procedures. With this method, contour diagrams of degree of saturation can be produced, making it possible to visualize the propagation of the saturated region.

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Section: Introductionmentioning

confidence: 99%

Measurement of Degree of Saturation on Model Ground by Digital Image Processing

Yoshimoto

Orense

Tanabe

et al. 2011

Soils and Foundations

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“…This correction varies with the counting rate and thus will cause the gamma-ray attenuation equation (Davidson, Biggar, and Nielsen, 1963) In R/R Q "-u ox (Grodstein, 1957). Gurr (1962) experimentally determined the mass absorption coefficient of water to be 2 0.0856 cm. /g.…”

Section: T = Resolving Time (Min/count)mentioning

confidence: 99%

Soil water redistribution during evaporation

Fritton

1968

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“…IN studying water transport in soil columns, the water distribution and the changes in distribution are often measured by the gamma transmission method, using a single source (Gurr, 1962;Davidson et al, 1963;Groenevelt et al, 1969).…”

Section: Introductionmentioning

confidence: 99%

Gamma Radiation for Measuring Water Contents in Soil Columns With Changing Bulk Density

Olesen¹

1973

Journal of Soil Science

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Water profiles in soil columns were measured by the single-source gamma radiation method. Together with the normal attenuation equation, linear or parabolic equations for the relation between bulk density and volumetric water content were used. T o compensate for moderate changes in the bulk density during the experiment both initial and final bulk density and the water content were used in the water profile estimations.For a sandy loam soil, the radiation method without any corrections for bulk density changes resulted in a mean error of the volumetric water content estimation of 0.035 cm3 when the water content changed from 0.35 to 0.15 cm3 and3. By correction for changing bulk density by means of a linear or a parabolic equation the maximum difference between real and estimated water content was oaoog and 0*002 c m S ~m -~, respectively. Applying the latter method and a count of 106 the error of a single water content measurement was 0.004 cm3 Introduction IN studying water transport in soil columns, the water distribution and the changes in distribution are often measured by the gamma transmission method, using a single source (Gurr, 1962; Davidson

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Use of Gamma Rays in Measuring Water Content and Permeability in Unsaturated Columns of Soil

Cited by 63 publications

References 0 publications

Measurement of Degree of Saturation on Model Ground by Digital Image Processing

Measurement of Degree of Saturation on Model Ground by Digital Image Processing

Soil water redistribution during evaporation

Gamma Radiation for Measuring Water Contents in Soil Columns With Changing Bulk Density

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