HR: 11:45h
AN: H32B-06 INVITED     [Abstracts]
TI: Sensitivity and Resolution of Tomographic Pumping Tests in an Alluvial Aquifer
AU: * Bohling, G C
EM: geoff@kgs.ku.edu
AF: Kansas Geological Survey, 1930 Constant Avenue, Lawrence, KS 66047, United States
AB: A number of investigators have proposed hydraulic tomography, the simultaneous analysis of responses to multiple well tests or flow system stresses, as a means to obtain a higher resolution characterization of aquifer flow and transport properties than can be obtained from traditional aquifer test analysis. In this presentation I use first-order sensitivity analysis and resolution matrix analysis to quantitatively examine the resolution provided by a set of tomographic pumping tests in an alluvial aquifer. The latter technique is commonly employed in geophysical tomography and promises to be of considerable use in tomographic approaches to hydrogeologic inverse problems as well. In particular, I compare the sensitivity and resolution provided by fully transient and steady-shape approaches to the estimation of the hydraulic conductivity (K) field. The steady-shape approach takes advantage of the rapid establishment of constant gradients within the region surrounding the pumping well, comparing observed drawdown differences within this region to drawdown differences predicted by a steady- state model. The results demonstrate that either approach resolves K variations only within a certain limited distance of the pumping wells and observation points, but that, relative to the transient approach, the steady- shape approach tends to filter out the influence of unresolved property variations outside the region of investigation.
DE: 1846 Model calibration (3333)
DE: 1869 Stochastic hydrology
DE: 1894 Instruments and techniques: modeling
DE: 1895 Instruments and techniques: monitoring
SC: Hydrology [H]
MN: 2007 Joint Assembly