那棱格勒河流域氢氧同位素特征及其指示意义

In this study, 63 samples comprising atmospheric precipitation, river water, groundwater, lake surface brine, and intercrystaline bittern were collected from the Nalenggele River. These samples were analyzed to assess the distribution characteristics and influencing factors of hydrogen and oxygen isotope, as well as deuterium surplus. The key findings are as follows: (1) The D and 18O values of atmospheric precipitation in the study area are higher than the average values across China. Due to the combined effect of evaporation and water vapor recirculation, the slope of the meteoric water line in the study area is lower than the global meteoric water line but higher than that of other drainage basins in the northwest arid zone. The East Asian monsoon, which transports water vapor over long distances, is the primary factor contributing to the low deuterium surplus in the atmospheric precipitation of the study area in August. (2) The river water line slope in the study area is smaller than that of the global meteoric water line. The deuterium surplus in river water is negatively correlated with 18O and TDS (Total dissolved solids), which is attributed to isotopic fractionation caused by evaporation. The river is primarily recharged by atmospheric precipitation from southern mountainous areas. Variations in isotopic elevation effects result in differences in D and 18O values across different sections of the Nalenggele River. (3) Groundwatersurface water interactions, along with the groundwater recharge from multiple sources in the southern mountainous areas, cause the slope and intercept of the groundwater lines to be larger than those of both the global and local meteoric water lines. (4) The hydrogen and oxygen isotopes of surface brine and intercrystaline brine show an oxygen drift phenomenon, with deuterium surplus values falling below zero. This is attributed to excessive fractionation induced by evaporation. The deuterium surplus value in intercrystaline is lower than that of surface brine, likely due to the dissolution and filtration of salt minerals.