Transport modeling of hydrogen and oxygen stable isotopes from rain water to groundwater in Golmud drainage area of Qaidam Basin, P.R. China

The hydrogen and oxygen stable isotopic compositions of water bodies contain abundant hydrological information which may indicate to hydrological cycle mechanisms. Current qualitative analysis method is normally aimed at the slope and the intercept of δD -δ¹⁸O regression lines, other statistical characteristics are ignored. The improvement is limited by the method itself. In this paper, a quantitative model was established based on the nested modeling of hydrological balance and isotopic fractionation-mixing processes. The model focus on the distribution of samples in spite of the value of single sample. It uses stochastic parameters which represent the variation of environmental conditions to simulate the isotopes transport from rain water to groundwater in Golmud drainage area. The simulation shows that the translation rate from the infiltrated rain water to groundwater is in the range from 44.0% to 53.8% and the residua amount of the initial water which participates evaporative process is in the range from 6.7% to 16.4% on total groundwater. Further studies for model improvement should focus on the reducing of artificial errors caused in the calibration process.