Hydrogen and oxygen isotopic records in monthly scales variations of hydrological characteristics in the different landscape zones of alpine cold regions

Abstract

Monthly scale variations in stable isotopic composition in precipitation and various water bodies were analyzed in this study using data collected from a field station. Experimental observation was performed to analyze processes in the glacier-snow zone, alpine cold desert zone, marsh meadow zone, alpine shrub zone, and mountain grassland zone based on the isotopic and hydrochemical analyses of glacier, snow, frozen soil, groundwater, and other water sources in the headwater catchment of the alpine cold region. δ18O and δD values of precipitation and various water bodies in Mafengou River Basin exhibited strong seasonal variations. Precipitation and various water bodies were rich in δ18O and δD during the wet season and relatively negative in δ18O and δD during the dry season. The isotopic content of various water bodies in Mafengou River Basin was dependent on temperature, elevation of the recharge area, and amount of precipitation. Lower temperatures were typically associated with lower δ18O and δD values and are believed to be mainly responsible for the seasonal patterns observed in the isotopic values of various water bodies in Mafengou River Basin in the alpine cold region. Seasonal variations were larger in streams where recent precipitation is the main source of the flow and smaller in streams where groundwater is the dominant source of water.