HR: 1340h
AN: H33F-0532    [Abstracts]
TI: Flow Dimension Analysis of Pumping Tests in Geometric and Random Fields
AU: * Bowman, D O
EM: DoBowman@aol.com
AF: The University of Mississippi, 118 Carrier Hall, University, MS 38677 United States
AU: Holt, R M
EM: rmholt@olemiss.edu
AF: The University of Mississippi, 118 Carrier Hall, University, MS 38677 United States
AU: Roberts, R M
EM: rmrober@sandia.gov
AF: Sandia National Laboratories, 4100 National Parks Hwy, Carlsbad, NM 88220 United States
AB: The generalized radial flow approach is increasingly used to interpret hydraulic tests. The flow dimension of a hydraulic test can be estimated directly from the second derivative of pumping test drawdown versus log time. Previous studies have shown that flow dimension can be described as the change in cross-sectional area of flow and radial distance from the borehole. Using this relationship, we have developed a simple algorithm that generates geometries that correspond to arbitrary flow dimensions. We validated this approach using numerical pumping test simulations in fields mirroring the geometries coupled with curve fitting methods. Our results establish a direct link between physical heterogeneity and flow-dimension. To illustrate the usefulness of flow-dimension for interpreting information about heterogeneity, we simulated pumping tests in spatially correlated random fields. We noted significant changes in flow dimension when the advancing drawdown front encountered strong, contrasting heterogeneities. Using data from randomly located pumping wells, it may be possible to characterize the correlation length of the heterogeneous system. We believe flow dimension can be used with geologically-based conceptual hydrologic models to constrain heterogeneity characteristics in real aquifers.
DE: 1800 HYDROLOGY
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting