Groundwater Vulnerability Assessment: Hydrogeologic Perspective and Example from Salinas Valley, California

  1. Dennis L. Corwin,
  2. Keith Loague and
  3. Timothy R. Ellsworth
  1. Graham E. Fogg,
  2. Eric M. Labolle and
  3. Gary S. Weissmann

Published Online: 18 MAR 2013

DOI: 10.1029/GM108p0045

Assessment of Non-Point Source Pollution in the Vadose Zone

Assessment of Non-Point Source Pollution in the Vadose Zone

How to Cite

Fogg, G. E., Labolle, E. M. and Weissmann, G. S. (1999) Groundwater Vulnerability Assessment: Hydrogeologic Perspective and Example from Salinas Valley, California, in Assessment of Non-Point Source Pollution in the Vadose Zone (eds D. L. Corwin, K. Loague and T. R. Ellsworth), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM108p0045

Author Information

  1. Hydrologic Sciences, University of California, Davis, Ca

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1999

ISBN Information

Print ISBN: 9780875900919

Online ISBN: 9781118664698

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Keywords:

  • Groundwater—Pollution—Computer Simulation;
  • Nonpoint source pollution—Computer Simulation;
  • Zone of aeration—Computer Simulation

Summary

Vulnerability of groundwater to contamination has typically been addressed by analysis or inference of near-surface hydrologic processes. Yet, in many basins like the Salinas Valley, California, shallow groundwater quality has already been degraded over large areas by nitrates, pesticides, salinity from irrigation, or other contaminants. The ultimate impact of this contamination on deeper groundwater quality during the decades, centuries or millennia to come is a highly relevant issue. We demonstrate an approach to groundwater vulnerability assessment that emphasizes important geologic features in a stochastic-geostatistical framework and incorporates information on both shallow and deep groundwater flow and contaminant transport in the context of a circulating groundwater system. The approach complements more common, shallow investigative approaches, which emphasize source inventory, soil characteristics, and vadose-zone flow and transport. Results from an assessment of groundwater vulnerability to nitrate contamination in the Salinas Valley agree with observed regional patterns in groundwater nitrate concentrations.