Water Table Uncertainties due to Uncertainties in Structure and Properties of an Unconfined Aquifer          下载免费PDF全文

Juerg Hauser  Florian Wellmann  Mike Trefry 《Ground water》2018,56(2):251-265

We consider two sources of geology‐related uncertainty in making predictions of the steady‐state water table elevation for an unconfined aquifer. That is the uncertainty in the depth to base of the aquifer and in the hydraulic conductivity distribution within the aquifer. Stochastic approaches to hydrological modeling commonly use geostatistical techniques to account for hydraulic conductivity uncertainty within the aquifer. In the absence of well data allowing derivation of a relationship between geophysical and hydrological parameters, the use of geophysical data is often limited to constraining the structural boundaries. If we recover the base of an unconfined aquifer from an analysis of geophysical data, then the associated uncertainties are a consequence of the geophysical inversion process. In this study, we illustrate this by quantifying water table uncertainties for the unconfined aquifer formed by the paleochannel network around the Kintyre Uranium deposit in Western Australia. The focus of the Bayesian parametric bootstrap approach employed for the inversion of the available airborne electromagnetic data is the recovery of the base of the paleochannel network and the associated uncertainties. This allows us to then quantify the associated influences on the water table in a conceptualized groundwater usage scenario and compare the resulting uncertainties with uncertainties due to an uncertain hydraulic conductivity distribution within the aquifer. Our modeling shows that neither uncertainties in the depth to the base of the aquifer nor hydraulic conductivity uncertainties alone can capture the patterns of uncertainty in the water table that emerge when the two are combined.  相似文献   

Homogenization of granular material modeled by a three-dimensional discrete element method     

C. Wellmann  C. Lillie  P. Wriggers 《Computers and Geotechnics》2008,35(3):394-405

A homogenization strategy for granular materials is presented and applied to a three-dimensional discrete element method (DEM), that uses superellipsoids as particles. Macroscopic quantities are derived from the microscopic quantities resulting from a DEM simulation by averaging over representative volume elements (RVEs). The implementation of an RVE is described in detail regarding the definition and discretization of the RVE boundary. The homogenization strategy is validated by DEM simulations of compression and shear tests of cohesionless granular assemblies. Finally, an elasto-plastic material model is fitted to the resulting stress–strain curves.  相似文献   

Three-Dimensional Structural Geological Modeling Using Graph Neural Networks     

Hillier  Michael  Wellmann  Florian  Brodaric  Boyan  de Kemp  Eric  Schetselaar  Ernst 《Mathematical Geosciences》2021,53(8):1725-1749

Mathematical Geosciences - Three-dimensional structural geomodels are increasingly being used for a wide variety of scientific and societal purposes. Most advanced methods for generating these...  相似文献   

Assessing the Perth Basin geothermal opportunity: Preliminary results from simulations of heat transfer and fluid flow     

Heather A. Sheldon  Thomas Poulet  J. Florian Wellmann  Klaus Regenauer-Lieb  Mike Trefry  Franklin G. Horowitz  Klaus Gessner 《Journal of Geochemical Exploration》2009

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