Performance evaluation of groundwater model hydrostratigraphy from airborne electromagnetic data and lithological borehole logs

Pernille Aabye Marker, N. Foged, X. He, A. V. Christiansen, J. C. Refsgaard, E. Auken, Peter Bauer-Gottwein

Research output: Contribution to journalJournal articleResearchpeer-review

439 Downloads (Pure)

Abstract

Large-scale hydrological models are important decision support tools in water resources management. The largest source of uncertainty in such models is the hydrostratigraphic model. Geometry and configuration of hydrogeological units are often poorly determined from hydrogeological data alone. Due to sparse sampling in space, lithological borehole logs may overlook structures that are important for groundwater flow at larger scales. Good spatial coverage along with high spatial resolution makes airborne electromagnetic (AEM) data valuable for the structural input to large-scale groundwater models. We present a novel method to automatically integrate large AEM data sets and lithological information into large-scale hydrological models. Clay-fraction maps are produced by translating geophysical resistivity into clay-fraction values using lithological borehole information. Voxel models of electrical resistivity and clay fraction are classified into hydrostratigraphic zones using k-means clustering. Hydraulic conductivity values of the zones are estimated by hydrological calibration using hydraulic head and stream discharge observations. The method is applied to a Danish case study. Benchmarking hydrological performance by comparison of performance statistics from comparable hydrological models, the cluster model performed competitively. Calibrations of 11 hydrostratigraphic cluster models with 1-11 hydraulic conductivity zones showed improved hydrological performance with an increasing number of clusters. Beyond the 5-cluster model hydrological performance did not improve. Due to reproducibility and possibility of method standardization and automation, we believe that hydrostratigraphic model generation with the proposed method has important prospects for groundwater models used in water resources management.
Original languageEnglish
JournalHydrology and Earth System Sciences
Volume19
Issue number9
Pages (from-to)3875-3890
Number of pages16
ISSN1027-5606
DOIs
Publication statusPublished - 2015

Keywords

  • Benchmarking
  • Boreholes
  • Calibration
  • Compressed sensing
  • Decision support systems
  • Electric discharges
  • Groundwater
  • Groundwater flow
  • Hydraulic conductivity
  • Hydrology
  • Importance sampling
  • Lithology
  • Magnetometers
  • Water resources
  • Well logging
  • Airborne electromagnetic
  • Comparison of performance
  • Decision support tools
  • Geophysical resistivity
  • Groundwater modeling
  • High spatial resolution
  • Large scale hydrological model
  • Water resources management
  • Groundwater resources

Fingerprint

Dive into the research topics of 'Performance evaluation of groundwater model hydrostratigraphy from airborne electromagnetic data and lithological borehole logs'. Together they form a unique fingerprint.

Cite this