43. Discharge Pattern in the Gunt Valley, Western Pamir, with respect to δ²H, δ¹⁸O and Hydrochemistry

A three years lasting isotope hydrological study has been performed in the 14,000 km² catchment of river Gunt in the western Pamir in Tajikistan to resolve the contributions of different components to the total run-off out of the catchment. River samples have been taken from about 30 locations and precipitation from five stations in this high-alpine and partly glaciated region both in a monthly interval. Precipitation as important initial parameter was shown to originate from different wind systems tracing regionally the isotopic composition in time. Within the catchment, the subcatchments group with respect to deuterium excess of their waters. This strengthens the assumption of the varying influence of different wind systems. Along with the isotopic composition, hydrochemistry of the river waters varies in an annual cycle as result of a varying contribution of groundwater and/or melt water. Similarly, with these tracers the low-energy flow of the eastern part of the valley can be clearly separated from the dominating fraction from the high-energy flow in the western part.