Seawater intrusion in the southern Po Plain, Italy: managing a geologic and historical heritage

Irrigation in low-lying coastal plains may enhance the formation of fresh groundwater lenses and counteract salinization of groundwater and soil. This is discussed for the unconfined aquifer in the coastal plain near Ravenna, Italy. In this study area for example, a freshwater lens originates from an infiltration ditch used as a water reservoir for spray irrigation. Such incidental aquifer recharge practice from irrigation currently provides the only active freshening of an overall saline to brackish aquifer. The extend of the freshwater lens is controlled by the presence of drainage ditches, water level in ditches and rate of sea level rise. An integrated planning of irrigation within the water management of the coastal zone is necessary to have maximum benefits for freshening of the aquifer and making optimal use of the existing water and irrigation infrastructure.