The present database was established primarily on the basis of 245 water samples obtained from the Quaternary confined aquifers in 78 hydrologic boreholes recovered during 1960~1985.  The analytic items include the concentrations of K+, Na+, Ca²+, Mg²+, NH4+, Al³+, Cl-, HCO₃-, CO₃₂-, and SO₄₂-, and the values of PH and temperatures.  There were 5 Quaternary aquifers (I-V, from coretop downward) and 1 phreatic (on the core toppest) defined.  Of which, 24 water samples come from aquifer I, 63 from aquifer II, 53 from aquifer III, 70 from aquifer IV, and 35 from aquifer V.  When analysis, parallel test was applied to monitor the precision.  Analytic result was checked according to equilibrium relation of the sum of cations and anions (units in meq/l), and would be retested if the errors were beyond the permissive range.
    In order to study the movement of saltwater-freshwater interfaces in the confined aquifers, total dissolved solids (TDS) in groundwater was used as index of water quality.  Artificial neural network applied as a tool to simulation of the TDS distribution in those 5 aquifers. The results demonstrated that TDS distribution in groundwater, which is in fully agreement with the occurrence of 4-7 marine transgressions in intensity in the study area during Quaternary, is affected by sea level fluctuation.  Saltwater in aquifers IV and V is very localized but fluctuated apparently.  Leakage processes, which may result from groundwater withdraw, most likely influence their movement.  After groundwater formation, leakage action in local area can cause mixing of different layers of groundwater and thus change the water quality.  Data comparison in aquifers II and III were made between 1960s and 1980s.  The result indicates that the freshwater tend to flow outward (northwest and southeastward) from Shanghai city to its suburb area.  This phenomenon is interpreted as heavily reinjection of the freshwater after 1980s, to prevent large-scale subsidence that had occurred during 1960s, due to intensifying human activity, such as underground water exploitation.