The use of geophysical imaging for improved monitoring and management of saltwater intrusion
Saltwater intrusion poses a high level of risk to fresh water resources in coastal communities throughout Canada and the world. Saltwater intrusion is driven by withdrawal of groundwater from aquifers, and by rising sea level. The goal of this work is to demonstrate the usefulness of geophysical methods (electrical resistivity tomography and distributed temperature sensing) for improved monitoring and management of saltwater intrusion at the basin scale. These methods, which are similar to those used in medical tomography, allow for mapping the distribution of saltwater intrusion. This study is focused on the Monterey Bay groundwater basin, in Northern California. This region is under major threat from saltwater intrusion, and represents an ideal environment for developing and testing new methodologies. The outcome of this proposal will be three fold: 1) the development of an improved inversion algorithm for dealing with large datasets such as the one under consideration, 2) testing and assessing the role of distributed temperature sensing for improved understanding of surface water recharge, and 3) and assessment of the value of electrical resistivity data for long-term monitoring of saltwater intrusion.