How is saltwater intrusion in coastal aquifers analyzed and managed?

Saltwater intrusion occurs when pumping or sea level rise allows denser seawater to migrate into freshwater aquifer. Analysis: Ghyben-Herzberg approximation (interface depth = 40 * head above sea level for static conditions), sharp interface models, or variable-density flow models (SEAWAT, SUTRA) for transient analysis. Management: (1) Pumping reduction or redistribution, (2) Injection barriers creating freshwater ridge, (3) Extraction barriers pumping saltwater, (4) Recharge enhancement, (5) Monitoring wells with electrical conductivity sensors. Climate change increases vulnerability through sea level rise and reduced recharge.