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Solute transport and retention in three‐dimensional fracture networks
Author(s) -
Cvetkovic Vladimir,
Frampton Andrew
Publication year - 2012
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2011wr011086
Subject(s) - exponent , residence time (fluid dynamics) , range (aeronautics) , statistics , dispersion (optics) , mathematics , fracture (geology) , advection , boundary (topology) , geology , soil science , physics , geotechnical engineering , materials science , mathematical analysis , thermodynamics , philosophy , linguistics , optics , composite material
Resolving the hydrodynamic control of retention is an important step in predictive modeling of transport of sorbing tracers in fractured rock. The statistics of the transport resistance parameter β [T/L] and the related effective active specific surface area s f [1/L] are studied in a crystalline rock volume on a 100 m scale. Groundwater flow and advective transport are based on generic boundary conditions and realistic discrete fracture networks inferred from the Laxemar site, southeast Sweden. The overall statistics of β are consistent with statistics of the water residence time τ ; the moments of β vary linearly with distance, at least up to 100 m. The correlation between log τ and log β is predominantly linear, however, there is significant dispersion; the parameter s f strongly depends on the assumed hydraulic law (theoretical cubic or empirical quadratic). Fast and slow trajectories/segments in the network determine the shape of the β distribution that cannot be reproduced by infinitely divisible model over the entire range; the low value range and median can be reproduced reasonably well with the tempered one‐sided stable density using the exponent in the range 0.35–0.7. The low percentiles of the β distribution seems to converge to a Fickian type of behavior from a 50 to 100 m scale.