Hydrogeochemical Characteristics of Groundwater in the Karst Region, Southwest China

Groundwater is a very important source for drinking and irrigation in the karst area, and therefore understanding the hydrogeochemistry of karst water is extremely significant. Groundwater were collected, and major chemical compositions were measured to analyse the geochemical processes in Guiyang-Anshun, southwest China. The chemical compositions of the groundwater of the study area are dominated by Ca2+, Mg2+, HCO3-, SO42-, which have been derived largely from dissolution of carbonate rocks (limestone and dolomite). Compared to the rural areas, TDS value is higher in the city centre. Chloride as a conservative tracer can be used to discuss the source of main ions in the groundwater. In this case, we support that high concentrations of Ca2+, Mg2+, Na+ are observed with low Chloride concentration in the regional groundwater.