Abstract:

Thai Binh is a coastal province of Red River Delta, where having Holocene aquifers were distributed with complex geochemical conditions (intermingling ofsalt, brackish and fresh water zones). This aquifer is affected directly by rainfall and total amount of calculated water recharge for this aquifer is about 345.460 m3/day. In addition, the water level of aquifer also is affected by tides and rivers and the fluctuation of the groundwater level is varied with the change of tide in the range 1.5 ÷ 3.0 km from the shoreline. The total amount of sea and river water recharging to this aquifer is 300 m3/day. With the recharge of rainfall and surface water, the area of saltwater zone was narrowed about 180 square kilometer, from 700.5 square kilometer in 1996 to 521.1 square kilometer in 2014. Under the same coditions of rainfall and sea level rise, the simulation results of VISUAL MODFLOW and SEAWAT models forecast to 2100, the salt water area zones are continues to shrink is about 103.5 square kilometer and groundwater storage in this aquifer is 860 million cubic meter.