A total of 252 water samples were collected from 42 sites across the upper Han River
basin during the time period from 2005-2006. Major ions (Cl(-), NO3(-), SO4(2-), HCO3(-),
Na+, K+, Ca2+ and Mg2+), Si, water temperature, pH, EC and TDS were determined and
consequently correlation matrix, analysis of variance, factor analysis and principal
component analysis were performed in order to identify their seasonal variations and
atmospheric inputs into river solutes. The results reveal that pH, EC, TDS, Cl(-),
SO4(2-), HCO3(-), Ca2+ and Mg2+, K+ and Si generally tend to show the minimum compositions
in months belong to the rainy season, while the dry season for NO3(-) and Na+. NO3(-),
Mg2+ and Si have the maximum concentrations in months belong to the rainy season.
By comparing the major ions relating to hydrological regime, NO3(-), contrary to other
elements, has higher concentration in the rainy season. The overall water quality
is non-polluted, while there are indications of enrichment of inorganic anions including
NO3(-) causing water entrophication in the near future. The atmospheric inputs contribute
to river solutes is limited with a mean inputs of approximate 1% in the basin. The
understanding of the major ion dynamics would help water quality conservation in the
basin for China's interbasin water transfer project.