A field assessment of the value of steady shape hydraulic tomography for characterization of aquifer heterogeneities

Abstract

[1] Hydraulic tomography is a promising approach for obtaining information on variations in hydraulic conductivity on the scale of relevance for contaminant transport investigations. This approach involves performing a series of pumping tests in a format similar to tomography. We present a field-scale assessment of hydraulic tomography in a porous aquifer, with an emphasis on the steady shape analysis methodology. The hydraulic conductivity (K) estimates from steady shape and transient analyses of the tomographic data compare well with those from a tracer test and direct-push permeameter tests, providing a field validation of the method. Zonations based on equal-thickness layers and cross-hole radar surveys are used to regularize the inverse problem. The results indicate that the radar surveys provide some useful information regarding the geometry of the K field. The steady shape analysis provides results similar to the transient analysis at a fraction of the computational burden. This study clearly demonstrates the advantages of hydraulic tomography over conventional pumping tests, which provide only large-scale averages, and small-scale hydraulic tests (e.g., slug tests), which cannot assess strata connectivity and may fail to sample the most important pathways or barriers to flow.Citation: Bohling, G. C., J. J. Butler Jr., X. Zhan, and M. D. Knoll (2007), A field assessment of the value of steady shape hydraulic tomography for characterization of aquifer heterogeneities, Water Resour. Res., 43, W05430,

Estimation of heterogeneous aquifer parameters using centralized and decentralized fusion of hydraulic tomography data

“…During the last decade, HT has been intensively studied both numerically and experimentally to assess its performance with a few field applications (Straface et al, 2007;Bohling et al, 2007). HT studies have covered several flow conditions, ranging from steady-state flow (Yeh and Liu, 2000) to transient flow in both confined and unconfined aquifers (Cardiff and Barrash, 2011).…”

The hydraulic conductivity structure of gravel-dominated vadose zones within alluvial floodplains

“…A broad-scale non-invasive survey technique to investigate the subsurface would potentially allow rapid and broad spatial scale estimation at potentially fine spatial resolutions of vadose zone heterogeneity, compared to other point scale techniques which provide only local estimates of hydraulic properties (Bohling et al, 2007). The point-scale techniques can be used to ground-truth the broad-scale survey.…”

Joint interpretation of sequential pumping tests in unconfined aquifers

“…They include numerical studies [e.g., Gottlieb and Dietrich, 1995;Yeh and Liu, 2000;Bohling et al, 2002;Yeh, 2005, 2006;Fienen et al, 2008;Ni and Yeh, 2008;Castagna and Bellin, 2009;Xiang et al, 2009;Liu and Kitanidis, 2011], followed by laboratory sandbox studies [e.g., Liu et al, 2002;Brauchler et al, 2003;Illman et al, 2007;Liu et al, 2007;Illman et al, 2008;Yin and Illman, 2009;Illman et al, 2010;Berg and Illman, 2011a;Illman et al, 2012] and then experimental field studies [e.g. Bohling et al, 2007;Li et al, 2007;Straface et al, 2007;Cardiff et al, 2009;Illman et al, 2009;Berg and Illman, 2011b;Brauchler et al, 2011;Huang et al, 2011]. All these studies have consistently shown that transient HT can identify not only the pattern of the heterogeneous hydraulic conductivity field but also the variation of specific storage.…”