Coastal aquifers serve as major sources for freshwater supply in many
countries around the world, especially in arid and semi-arid zones. Many
coastal areas are also heavily urbanized, a fact that makes the need for
freshwater even more acute. Coastal aquifers are highly sensitive to
disturbances. Inappropriate management of a coastal aquifer may lead to
its destruction as a source for freshwater much earlier than other
aquifers which are not connected to the sea. The reason is the threat of
seawater intrusion. In many coastal aquifers, intrusion of seawater has
become one of the major constraints imposed on groundwater utilization.
As sea- water intrusion progresses, existing pumping wells, especially
those close to the coast, become saline and have to be abandoned. Also,
the area above the intruding seawater wedge is lost as a source of
natural replenishment to the aquifer. Despite the importance of this
subject, so far there does not exist a book that integrates our present
knowledge of seawater intrusion, its occurrences, physical mechanism,
chemistry, exploration by geo- physical and geochemical techniques,
conceptual and mathematical modeling, analytical and numerical solution
methods, engineering measures of combating seawater intrusion,
management strategies, and experience learned from case studies. By
presenting this fairly comprehensive volume on the state-of-the-art of
knowledge and ex- perience on saltwater intrusion, we hoped to transfer
this body of knowledge to the geologists, hydrologists, hydraulic
engineers, water resources planners, managers, and governmental policy
makers, who are engaged in the sustainable development of coastal fresh
ground- water resources.
