Field study of hydrogeologic characterization methods in a heterogeneous aquifer

Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

Bibliographische Detailangaben
Veröffentlicht in:Ground water. - 1979. - 49(2011), 3 vom: 15. Mai, Seite 365-82
1. Verfasser: Alexander, Matthew (VerfasserIn)
Weitere Verfasser: Berg, Steven J, Illman, Walter A
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2011
Zugriff auf das übergeordnete Werk:Ground water
Schlagworte:Comparative Study Evaluation Study Journal Article Research Support, Non-U.S. Gov't
Beschreibung
Zusammenfassung:Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.
Hydraulic conductivity (K) and specific storage (S(s)) are required parameters when designing transient groundwater flow models. The purpose of this study was to evaluate the ability of commonly used hydrogeologic characterization approaches to accurately delineate the distribution of hydraulic properties in a highly heterogeneous glaciofluvial deposit. The metric used to compare the various approaches was the prediction of drawdown responses from three separate pumping tests. The study was conducted at a field site, where a 15 m × 15 m area was instrumented with four 18-m deep Continuous Multichannel Tubing (CMT) wells. Each CMT well contained seven 17 cm × 1.9 cm monitoring ports equally spaced every 2 m down each CMT system. An 18-m deep pumping well with eight separate 1-m long screens spaced every 2 m was also placed in the center of the square pattern. In each of these boreholes, cores were collected and characterized using the Unified Soil Classification System, grain size analysis, and permeameter tests. To date, 471 K estimates have been obtained through permeameter analyses and 270 K estimates from empirical relationships. Geostatistical analysis of the small-scale K data yielded strongly heterogeneous K fields in three-dimensions. Additional K estimates were obtained through slug tests in 28 ports of the four CMT wells. Several pumping tests were conducted using the multiscreen and CMT wells to obtain larger scale estimates of both K and S(s). The various K and S(s) estimates were then quantitatively evaluated by simulating transient drawdown data from three pumping tests using a 3D forward numerical model constructed using HydroGeoSphere (Therrien et al. 2005). Results showed that, while drawdown predictions generally improved as more complexity was introduced into the model, the ability to make accurate drawdown predictions at all CMT ports was inconsistent
Beschreibung:Date Completed 12.08.2011
Date Revised 10.12.2019
published: Print
Citation Status MEDLINE
ISSN:1745-6584