Abstract:

 Mathematical statistical methods, as supplements for computer modeling, have many advantages in the study of hydrogeochemistry for the shallow groundwater.Descriptives, correlation and factor analyses have been carried out for the water quality data of the groundwater samples from the shallow weathering zone of red beds in the Sichuan basin.It was found that the dominant cation and anion are HCO-3 and Ca2+ respectively; the concentrations of HCO-3, Ca2+ and Mg2+ are in stabilization and in particular, the concentration of HCO-3 are steady with high values; the concentrations of Na++K+, SO2-4 and Cl- have high variations and are sensitive to many environmental parameters; the geochemical composition of the water samples were controlled by atmospheric precipitation and the mineral composition of the rock; freshwater with TDS＜1 g/L covers the most area with low TDS in the skirt and high TDS values in the central area of the basin and also TDS in local areas was controlled by atmospheric precipitation.

Key words: area shallow groundwater, mathematical statistics method, hydrogeochemistry, Sichuan basin