[Hydro-chemical Characteristics and Quality Assessment of Surface Water in Gongga Mountain Region].

The concentrations of major ions (K, Na, Ca, Mg, CO, HCO, Cl, and SO), heavy metals (Cu, Cd, Pb, and Zn), and nutrient elements (N and P) in surface water collected from Gongga Mountain region were analyzed to decipher their spatial distribution and assess the water quality. The descriptive statistics, Gibbs Figure, and triangular diagrams of anions and cations were employed, and single factor evaluation was conducted. The results showed that the average value of total dissolved solid (TDS) in Gongga Mountain region was 103.22 mg·L indicating low salinity, and the hydro-chemical type was HCO-Ca. For whole catchment, the major ion chemistry of river water was controlled by carbonate weathering, while the effect of atmospheric deposition was high in the eastern area. The overall concentrations of heavy metals and nutrient elements were low, and the eastern area had significantly higher concentrations than the west. The quality of surface water was good from the whole point of view, while that in the west was better than the east. It indicated that the spatial distribution was mainly controlled by natural factors, but the water of southeast slope had been affected by humans.