Geophysical Investigations

Abstract

Saltwater intrusion is the mass transport of saline waters into zones previously occupied by fresher waters. In hydrogeologic systems mass transport rates and pathways are determined by hydraulic gradients and the distribution of hydraulic conductivity. The configuration of the saltwater interface and its movement are determined by the configuration of the water table and the spatial variation in hydraulic conductivity. One objective of geophysical surveys in island and coastal environments is to help define the physical framework within which saltwater intrusion occurs. Geophysical methods which can distinguish geologic units on the basis of their physical properties, such as seismic methods, can be very useful even though they cannot detect saline waters directly.