Application of spectral analysis to determine hydraulic diffusivity of a sandy aquifer (Pingtung County, Taiwan)

Shih, David Ching‐Fang; Lin, Gwo‐Fong

doi:10.1002/hyp.1411

Cited by 23 publications

(13 citation statements)

References 12 publications

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“…They show that the external disturbance for these parameters is quite complicated. Similar phenomena were demonstrated in other studies (Shih et al, 1999Shih, 1999aShih, , 1999bShih, , 2000Shih, , 2002Shih and Lin, 2002;2004). In this study, relative ground water head supersede the actual ground water level due to losing record of reference level.…”

Section: Introductionsupporting

confidence: 90%

“…As such, data of the disturbed ground water levels, upon application of relevant boundary conditions, can be expressed mathematically by using the spectral relationships through time-frequency domain of tidal effects. With this approach, the spectral characteristics of field data can be used to solve for hydraulic diffusivity as a ratio of transmissivity and storage coefficient (Shih, 1999a,b;Shih and Lin, 2004). Therefore, it is an alternative approach to study aquifer parameters in a large scale by using data from a relevant setting of boundary conditions and water level fluctuation in observation wells.…”

Section: Introductionmentioning

confidence: 99%

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Spectral decomposition of periodic ground water fluctuation in a coastal aquifer

Shih

Lin

Jia

et al. 2008

Hydrological Processes

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This research accomplished by the descriptive statistics and spectral analysis of six kinds of time series data gives a complete assessment of periodic fluctuation in significant constituents for the Huakang Shan earthquake monitoring site. Spectral analysis and bandpass filtering techniques are demonstrated to accurately analyse the significant component. Variation in relative ground water heads with a period of 12Ð6 h is found to be highly related to seawater level fluctuation. Time lag is estimated about 3Ð78 h. Based on these phenomena, the coastal aquifer formed in an unconsolidated formation can be affected by the nearby seawater body for the semi-diurnal component. Fluctuation in piezometric heads is found to correspond at a rate of 1000 m h 1 . Atmospheric pressure presents the significant components at periods of 10Ð8 h and 7Ð2 h in a quite different type, compared to relative ground water head and seawater level.

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Section: Introductionsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Spectral decomposition of periodic ground water fluctuation in a coastal aquifer

Shih

Lin

Jia

et al. 2008

Hydrological Processes

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“…The methodology of stationary spectral analysis can be found in detail in the updated work of Bendat and Piersol (2000). Many advanced applications in geosciences for obtaining spectral estimates are also found in the relevant studies (Shih et al 1999Shih 1999aShih , b, 2000Shih , 2002 Lin 2002Lin , 2004Shih 2008;Shih et al 2008a, b). Detailed procedure and computation for spectral analysis can be reviewed on the above-mentioned studies.…”

Section: Spectral Analysismentioning

confidence: 93%

Sea level fluctuations on the east coast of Taiwan that overlie continental shelf break

Shih

Chen

Lin

et al. 2008

Stoch Environ Res Risk Assess

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Captured CO 2 could be deliberately injected into the ocean at great depth, where most of it would remain isolated from the atmosphere for centuries. CO 2 can be transported via pipeline or ship for release in the ocean or on the sea floor. No matter what for medium depth or deep sea, it appears that a potential area exists between 122-122.5°E and 21.8-22.3°N for CO 2 sequestration. The east coast of Taiwan can be a candidate for CO 2 temporary storage or transmitted plant. To have whole picture of assessment of sea level fluctuation, a completed statistical summary of seasonal sea level at six tidal gauge stations along the east coast of Taiwan is provided herein. Seasonal sea level time series is analyzed using spectral analysis in frequency domain to identify periodic component and phase propagation, especially for the astronomical-driven tidal effects. It identifies that the semi-diurnal and diurnal components in the resultant time series are related to astronomical tides M 2 , and K 1 and O 1 , respectively. It demonstrates a full analysis of sea level variations, and results can be useful when construction of testing or operating facilities on sea surface becomes desirable in the future.

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“…The literature on methods for assessing hydraulic diffusivity of porous media aquifers is vast. The most direct method is probably the inverse modelling of hydraulic head fluctuations regulated by groundwater flow equations (Gilmore 1992, Ha et al 2007, Guo et al 2010, Pacheco 2013 or spectral relationships (Shih and Lin 2004), because diffusivity is the unknown parameter in these equations or relationships. In line with this method is the analysis of river baseflows (Baloochestani 2008) or more specific algorithms such as the drawdown ratio technique (Neuman andWitherspoon 1972, Leahy 1976).…”

Section: Introductionmentioning

confidence: 99%

Bridging hydraulic diffusivity from aquifer to particle-size scale: a study on loess sediments from southwest Hungary

Pacheco

Landim

Szőcs

2015

Hydrological Sciences Journal

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In situ megascale hydraulic diffusivities (D) of a confined loess aquifer were estimated at various scales (10 ≤ L ≤ 1500 m) by a finite difference model, and laboratory microscale diffusivities of a loess sample by empirical formulas. A scatter plot reveals that D fits to a single power function of L, providing that microscale diffusivities are assigned to L = 1 m and that differences in diffusivity observed between micro-and megascales are assigned to medium heterogeneity appraised by variations in the curvature and slope of natural hydraulic head waves propagating through the aquifer. Subsequently, a general power relationship between D and L is defined where the base and exponent terms stand for the aquifer storage capability under a confined regime of flow, for the microscale hydraulic conductivity and specific yield of loess, and for the changes in curvature and slope of hydraulic head waves relative to values defined at unit scale.Relier les diffusivités hydrauliques de l'aquifère à l'échelle particulaire : une étude sur les loess du Sud-Ouest de la Hongrie Résumé Les diffusivités hydrauliques (D) in situ d'un aquifère captif loessique ont été estimées à différentes méga-échelles (10 ≤ L ≤ 1500 m) par un modèle aux différences finies tout comme les diffusivités de laboratoire l'ont été à la micro-échelle d'un échantillon de loess à partir de formules empiriques. Un diagramme montre que D s'ajuste à une fonction puissance de L à condition que les diffusivités microéchelle soient affectées à L = 1 m et que les différences de diffusivité observées chez les micro et les méga-échelles soient attribuées à l'hétérogénéité du milieu éstimée par les variations de courbure et de pente des ondes naturelles de charge hydraulique se propageant dans l'aquifère. En conséquence, une relation générale exponentielle entre D et L a été définie, où le terme de base et l'exposant représentent la capacité d'emmagasinement en nappe captive, la conductivité hydraulique et la porosité efficace du loess à microéchelle, et les changements de courbure et de pente des ondes de charge hydraulique par rapport aux valeurs définies à l'échelle unitaire.

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Application of spectral analysis to determine hydraulic diffusivity of a sandy aquifer (Pingtung County, Taiwan)

Cited by 23 publications

References 12 publications

Spectral decomposition of periodic ground water fluctuation in a coastal aquifer

Spectral decomposition of periodic ground water fluctuation in a coastal aquifer

Sea level fluctuations on the east coast of Taiwan that overlie continental shelf break

Bridging hydraulic diffusivity from aquifer to particle-size scale: a study on loess sediments from southwest Hungary

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