Using airborne geophysical surveys to improve groundwater resource management models

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Abstract

Increasingly, groundwater management requires more accurate hydrogeologic frameworks for groundwater models. These complex issues have created the demand for innovative approaches to data collection. In complicated terrains, groundwater modelers benefit from continuous high‐resolution geologic maps and their related hydrogeologic‐parameter estimates. The USGS and its partners have collaborated to use airborne geophysical surveys for near‐continuous coverage of areas of the North Platte River valley in western Nebraska. The survey objectives were to map the aquifers and bedrock topography of the area to help improve the understanding of groundwater‐surface‐water relationships, leading to improved water management decisions. Frequency‐domain heliborne electromagnetic surveys were completed, using a unique survey design to collect resistivity data that can be related to lithologic information to refine groundwater model inputs. To render the geophysical data useful to multidimensional groundwater models, numerical inversion is necessary to convert the measured data into a depth‐dependent subsurface resistivity model. This inverted model, in conjunction with sensitivity analysis, geological ground truth (boreholes and surface geology maps), and geological interpretation, is used to characterize hydrogeologic features. Interpreted two‐ and three‐dimensional data coverage provides the groundwater modeler with a high‐resolution hydrogeologic framework and a quantitative estimate of framework uncertainty. This method of creating hydrogeologic frameworks improved the understanding of flow path orientation by redefining the location of the paleochannels and associated bedrock highs. The improved models reflect actual hydrogeology at a level of accuracy not achievable using previous data sets.

Additional publication details

Publication type Conference Paper
Publication Subtype Conference Paper
Title Using airborne geophysical surveys to improve groundwater resource management models
DOI 10.4133/1.3445449
Year Published 2010
Language English
Publisher Society of Exploration Geophysicists
Contributing office(s) Crustal Geophysics and Geochemistry Science Center
Description 6 p.
Larger Work Type Book
Larger Work Subtype Conference publication
Larger Work Title Symposium on the Application of Geophysics to Engineering and Environmental Problems 2010
First page 309
Last page 314
Conference Title Symposium on the Application of Geophysics to Engineering and Environmental Problems 2010