Saline groundwater flow in the Yellow River delta, Chin

Saline groundwater occurs at depths shallower than 50 m in the southern Yellow River delta. Recent decreases in water flows in the lower Yellow River will affect the interactions among river water, groundwater, and seawater in the delta. There is concern that this will also affect saline groundwater flow, the relationship between saline groundwater and aquifer water, and groundwater use. We examined deep and shallow saline groundwater, the effects of Yellow River water, and the interaction of shallow groundwater and recharge water. The origins of salinity differ between shallow and deep saline groundwater depending on the area and flow system. Paleo-seawater which is formed in 4000-7500yr before is distributed at 10-20 m in depth at all over area but also distributed at 30 m in depth at inland northern area. At 10-20 m in depth, saline groundwater is affected by the upper shallow fresh groundwater that is recharged by Yellow River water. At 30 m in depth, salinity is strongly affected by present-day seawater. It is suggested that present- day seawater intrude to inland area, especially at the southern area.