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Boise Hydrogeophysical Research Site (Bhrs): Objectives, Design, Initial Geostatistical Results
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 12th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, Mar 1999, cp-202-00044
Abstract
The Boise Hydrogeophysical Research Site (BHRS) is a wellfield developed in a shallow,<br>coarse (cobble-and-sand), alluvial aquifer with the goal of developing cost-effective methods for<br>quantitatively characterizing the distribution of permeability in heterogeneous aquifers using<br>hydrologic and geophysical techniques. Responses to surface geophysical techniques (e.g., seismic,<br>radar, transient electromagnetics) will be calibrated against a highly characterized control volume<br>(the wellfield) with 3-D distributions of geologic, hydrologic, and geophysical properties determined<br>from extensive field measurements. Also, these data sets will be used to investigate relationships<br>between properties and to test petrophysical models. Well coring and construction methods, and the<br>well arrangement in the field, are designed to provide detailed control on lithology and to support<br>a variety of single-well, crosshole, and multiwell geophysical and hydrologic tests. Wells are<br>screened through the cobble-and-sand aquifer to a clay that underlies the BHRS at about 20 m depth.<br>In addition, the wellfield design optimizes well-pair distances and azimuths for determination of<br>short-range geostatistical structure. Initial geostatistical analysis of porosity data derived from<br>borehole geophysical logs indicates that the omnidirectional horizontal experimental variogram for<br>porosity (possible proxy for log permeability) is best fit with a nested periodic model structure.