Displacement of fresh water or groundwater by the advance of salt water due to its greater density, usually in coastal and estuarine areas but also by movement of brine from beneath a playa lake toward wells discharging fresh water. Encroachment occurs when the total head of the salt water exceeds that of adjacent fresh water. Syn: sea-water intrusion, salt-water intrusion, sea-water encroachment.
(Neuendorf, K.K.E. and others, 2005)