Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.advwatres.2017.08.017
Title (Primary) Geological heterogeneity: Goal-oriented simplification of structure and characterization needs
Author Savoy, H.; Kalbacher, T.; Dietrich, P. ORCID logo ; Rubin, Y.
Source Titel Advances in Water Resources
Year 2017
Department ENVINF; MET
Volume 109
Page From 1
Page To 13
Language englisch
Keywords Geological heterogeneity; Hydrofacies; Aquifer analog; Arrival times; Subsurface characterization
UFZ wide themes RU5
Abstract Geological heterogeneity, i.e. the spatial variability of discrete hydrogeological units, is investigated in an aquifer analog of glacio-fluvial sediments to determine how such a geological structure can be simplified for characterization needs. The aquifer analog consists of ten hydrofacies whereas the scarcity of measurements in typical field studies precludes such detailed spatial models of hydraulic properties. Of particular interest is the role of connectivity of the hydrofacies structure, along with its effect on the connectivity of mass transport, in site characterization for predicting early arrival times. Transport through three realizations of the aquifer analog is modeled with numerical particle tracking to ascertain the fast flow channel through which early arriving particles travel. Three simplification schemes of two-facies models are considered to represent the aquifer analogs, and the velocity within the fast flow channel is used to estimate the apparent hydraulic conductivity of the new facies. The facies models in which the discontinuous patches of high hydraulic conductivity are separated from the rest of the domain yield the closest match in early arrival times compared to the aquifer analog, but assuming a continuous high hydraulic conductivity channel connecting these patches yields underestimated early arrivals times within the range of variability between the realizations, which implies that the three simplification schemes could be advised but pose different implications for field measurement campaigns. Overall, the results suggest that the result of transport connectivity, i.e. early arrival times, within realistic geological heterogeneity can be conserved even when the underlying structural connectivity is modified.
Persistent UFZ Identifier
Savoy, H., Kalbacher, T., Dietrich, P., Rubin, Y. (2017):
Geological heterogeneity: Goal-oriented simplification of structure and characterization needs
Adv. Water Resour. 109 , 1 - 13 10.1016/j.advwatres.2017.08.017