Abstract:

During the summers of 1999 and 2000, sampling was carried out in Mt. Yulong, for the investigation of the spatial distribution of oxygen stable isotope in the atmospheric-glacial-hydro system and similar results obtained in the two years have confirmed our conclusion. There is an evident negative correlation between stable isotopic composition and air temperature precipitation amount, suggesting that there exits a strong "precipitation amount effect" in this typical monsoon temperate-glacier region. There are marked differences between the δ¹⁸O values in winter-accumulated snow, glacial meltwater, summer precipitation and glacier-feeding stream. Under the control of varied climatic conditions, spatial and temporal variations of above glacial hydro mediums are apparent. Isotopic depletion or fractionation and ionic changes had occurred during the phase-change and transformation processes of snow-ice, ice-meltwater, flowing of runoff and contact with bedrock. The variation of stable isotope in a runoff can reflect not only its own flowing process but also its different feeding sources.

Key words: stable isotopes, monsoon temperate-glacier, Mountain Yulong