Evaluating the Saltwater Intrusion to Aquifer Upper-Middle Pleistocene (qp_(2-3)) in Coastal Area of Tra Vinh Province Due to Groundwater Exploitation

摘要

Today, one of the most serious problems in Tra Vinh as other coastal provinces in Mekong Delta is the exploitation of groundwater for different purposes. In many cases, the aquifers are pumped or withdrawn with greater discharge to its natural ability, thus making seawater draw into the system [1]. This paper aims at evaluating the saltwater intrusion into aquifer upper-middle Pleistocene in Tra Vinh province area due to groundwater extraction. The calculated area includes 2,176 nodes, 2,079 elements, and grid steps Δx = Δy = 1,000 m. The program is set up to determine the interface between freshwater and saltwater which moves from the sea into the mainland of upper-middle Pleistocene aquifer. The calculating results show that at the initial point when pumping with outflow Q = 29,987 m~3/day, the toe interface in position is of 2,019 m from the sea, then with the time of exploitation t = 150,000 days, the interface moving into in the mainland is approximately 21,000-24,000 m. The calculation results enable managers and abstraction units to know the process of salt line by time in order to launch sound plan for exploitation.