GROUNDWATER MOVEMENT IN THE ESTUARINE DELTAIC REGION OF YANGTZE RIVER

Low-lying deltaic areas near the estuary accommodated high density populations with developed economic activities. Qidong City, which locates in the north of estuary of Yangtz River, is bounded by the coastline in the east and the estuary in the south. Groundwater in this area is affected by the tidal effect and is also of complex hydrochemical characteristics. FEMWATER in GMS (Groundwater Modeling System), a three-dimensional finite element computer model for simulating density-dependent flow and transport in variably saturated media, is applied to simulate groundwater movement in this deltaic region of Yangtz River. With the solution, the groundwater motion in the coastal and estuarine aquifer can be described as the similar characteristic of surface estuary. It has dual characteristics: (1) Water level goes up and down with flow flux such as rainfall, evaporation, etc; and (2) A kind of water level tidal fluctuations although they have been distorted