Abstract: Water samples of the Kaltamac glacier runoff and the non-glacier runoff were collected during July to August in 2016,meanwhile,statistically analysis,principle component analysis,Piper figure,Gibbs figure and forward model were conducted thereafter to analyze the hydrochemistry characteristics and identify the major ion sources of the two runoff water samples.Results showed that the two types of water are both alkaline,and the hydrochemical types included Ca²⁺-HCO₃^--SO₄^2-.However,pH,EC,TDS and major ions of the two water samples showed significant differences that the non-glacier runoff always showed higher values than the glacier runoff.All the ions showed similar source in glacier runoff while NO₃^- showed different source in the non-glacier runoff compared to other ions.Result of forward model showed that the contribution of atmospheric input,silicate weathering,carbonate weathering,and evaporite dissolution to the ion concentrations of the glacier and the non-glacier runoff were 10.47%,0.55%,65.61%,23.37% and 1.52%,19.57%,60.37%,18.54%,respectively.It can be seen that the ion concentrations of the glacier runoff was mainly affected by carbonate weathering,followed by the dissolution of evaporite; the ion concentrations of the non-glacier runoff was mainly affected by carbonate weathering,followed by the silicate weathering.The reason for the difference is that silicate weathering was more difficult to proceed than evaporite dissolution.The water-rock interaction time of the glacier runoff was shorter,so the contribution of silicates weathering was lower; while the water-rock interaction time of the non-glacier runoff was longer,so that the silicate weathering contribution is higher.This study can provide guidelines for water resource management for western regions in China.

Key words: glacierized catchment, non-glacier catchment, hydrochemical characteristics, controlling factors, Muztagata Mountain