the second grand challenge—development of a national knowledge bank on the geologic framework of coastal and marine regions.
Two aspects of water quality are important in the coastal zone: (1) saltwater intrusion into groundwater and (2) eutrophication of coastal ecosystems.
Around the perimeter of every continent and island is a coastal zone where continental (meteoric) groundwater meets seawater in the subsurface. Because of the difference in fluid density between freshwater and seawater, the interface between the two fluids extends inland from the coast in the subsurface. Global