A discussion of scale effects on hydraulic conductivity at a granitic site (El Berrocal, Spain)

Guimerà, Jordi; Vives, Luis; Carrera, Jesús

doi:10.1029/95gl01493

Cited by 41 publications

(31 citation statements)

References 6 publications

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“…This behavior, observed also by other authors (Guimerà et al, 1995;Schulze-Makuch and Cherkauer, 1995;Rovey and Cherkauer, 1995;Bromley et al, 2004;Qian et al, 2007), can be described through a nonlinear regression fit as well as by a power law interpolation function. In particular this law is represented by the following relation, obtained in logarithmic scale: ln k = 0:081 ln R−10:02 ð9Þ with a determination coefficient R 2 = 0.944, as shown in Fig.…”

Section: Resultsmentioning

confidence: 53%

Scaling analysis of hydraulic conductivity and porosity on a sandy medium of an unconfined aquifer reproduced in the laboratory

et al. 2010

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Section: Resultsmentioning

confidence: 53%

Scaling analysis of hydraulic conductivity and porosity on a sandy medium of an unconfined aquifer reproduced in the laboratory

et al. 2010

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“…Scale effects (increase in the value with increasing scale of measurement) on hydraulic conductivity have been reported in the literature. The median hydraulic conductivity increases with measurement scale (Guimerà et al 1995). The increase in hydraulic conductivity with larger scale is the result of spatial heterogeneities (Rovey 1998) and was described as scaling-up of hydraulic conductivity (Desbarats 1992).…”

Section: Calibration Of Hydraulic Conductivity Using the Numerical Momentioning

confidence: 98%

Modeling and Simulation of Baseflow to Drainage Ditches During Low-flow Periods

Goswami

Kalita

Mehnert

2009

Water Resour Manage

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Quantification of baseflow to drainage ditches is essential in understanding flow dynamics in a watershed. The mass balance estimation for a stream section may not give an accurate measure of the baseflow during low-flow periods due to the lack of accuracy in flow measurements in the flumes. Modeling may be useful for estimation of baseflow during low-flow periods. In this study, numerical and analytical solutions of the Boussinesq equation were used to simulate baseflow rates during low-flow periods in two watersheds, namely the Big Ditch watershed and the Upper Embarras River watershed in Illinois, USA. Additionally, MODFLOW was also used to simulate baseflow for these periods. At each site, a stream section of 200 m was selected for baseflow simulation and six observation wells were installed at one bank of each stream section for model calibration. A total of seven low-flow periods were considered for baseflow simulation. The mean baseflow rates simulated by the numerical model were higher than that simulated by the other two models. There is no significant difference between the mean baseflow rates simulated by the analytical model and MODFLOW. It was observed that proper estimation and/or measurement of model parameters were necessary for simulation of reliable baseflow rates. Since flow measurements during low-flow periods may include possible errors, the model results might also be acceptable for all practical purpose.

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“…The specific yield (S y ) and the specific storage (S s ) were estimated based on borehole sample analysis and assigned as spatially uniform, for the first unconfined aquifer as S y = 0.15, for the aquitard and for the second confined aquifer as S s = 0.00001 m −1 . Although all the hydraulic parameters were defined based on the field measurements, due to the modelling scale effect (Guimerà et al 1995;Zhang et al 2006;Zhang et al 2007) and limited spatial representativeness, they were still considered to be adjusted in the calibration process.…”

Section: Model Setupmentioning

confidence: 99%

Interactions of artificial lakes with groundwater applying an integrated MODFLOW solution

2017

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Artificial lakes (reservoirs) are regulated water bodies with large stage fluctuations and different interactions with groundwater compared with natural lakes. A novel modelling study characterizing the dynamics of these interactions is presented for artificial Lake Turawa, Poland. The integrated surface-water/groundwater MODFLOW-NWT transient model, applying SFR7, UZF1 and LAK7 packages to account for variably-saturated flow and temporally variable lake area extent and volume, was calibrated throughout 5 years (1-year warm-up, 4-year simulation), applying daily lake stages, heads and discharges as control variables. The water budget results showed that, in contrast to natural lakes, the reservoir interactions with groundwater were primarily dependent on the balance between lake inflow and regulated outflow, while influences of precipitation and evapotranspiration played secondary roles. Also, the spatio-temporal lakebed-seepage pattern was different compared with natural lakes. The large and fast-changing stages had large influence on lakebed-seepage and water table depth and also influenced groundwater evapotranspiration and groundwater exfiltration, as their maxima coincided not with rainfall peaks but with highest stages. The mean lakebed-seepage ranged from~0.6 mm day −1 during lowest stages (lake-water gain) to~1.0 mm day −1 during highest stages (lake-water loss) with largest losses up to 4.6 mm day −1 in the peripheral zone. The lakebed-seepage of this study was generally low because of low lakebed leakance (0.0007-0.0015 day −1 ) and prevailing upward regional groundwater flow moderating it. This study discloses the complexity of artificial lake interactions with groundwater, while the proposed front-line modelling methodology can be applied to any reservoir, and also to natural lake interactions with groundwater.

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A discussion of scale effects on hydraulic conductivity at a granitic site (El Berrocal, Spain)

Cited by 41 publications

References 6 publications

Scaling analysis of hydraulic conductivity and porosity on a sandy medium of an unconfined aquifer reproduced in the laboratory

Scaling analysis of hydraulic conductivity and porosity on a sandy medium of an unconfined aquifer reproduced in the laboratory

Modeling and Simulation of Baseflow to Drainage Ditches During Low-flow Periods

Interactions of artificial lakes with groundwater applying an integrated MODFLOW solution

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