Author(s): Tran Dang An; Maki Tsujimura; Vo Le Phu; Truong Thu Hang
Linked Author(s):
Keywords: Groundwater flow system; Hydrogeological processes; Seawater intrusion; Mekong Delta; Soc Trang
Abstract: In many parts of the world, especially in coastal regions, excessive groundwater extraction and changing recharge rate have resulted in many serious groundwater-related problems such as saline water, arsenic contamination and land subsidence. In this research, we used multiple techniques such as hydrogeochemistry, stable isotopes signatures, statistic analysis to ascertain the effects of changes in groundwater flow on groundwater evolution in coastal areas of Soc Trang province in the Mekong Delta, Vietnam. The results show that almost groundwater in this province has similar recharged areas, however groundwater characteristics between shallow and deep aquifers were clearly different. The continued expanding of groundwater depression areas caused salt intrusion in coastal aquifers. Seawater has intruded directly into shallow aquifers (Holocene, upper Pleistocene), while some parts of middle Pleistocene aquifer was affected by saline diffusion. In addition, the intrusion of paleo-saline groundwater to fresh layers has been occurring excessively in deeper aquifers (middle Pleistocene, Pliocene and Miocene). This situation requires urgent solutions for sustainable use of water sources in the contexts of climate changes and rapidly increasing water demand in coastal areas as well as at the whole Mekong Delta.
Year: 2014