新疆焉耆盆地水环境氢氧同位素特征及其指示作用

根据焉耆盆地开都河水及其两岸地下水中的氢氧稳定同位素资料及氘过量参数(d)值,分析了焉耆盆地内不同水体的δ(D)、δ(18O)和d值的分布规律,并得到地下水的主要补给来源及其与开都河水的相互作用关系;地下水的δ(D)在-87.60‰～-61.82‰间,δ(18O)在-10.90‰～-9.73‰间;开都河水的δ(D)在-71.95‰～-58.58‰间,δ(18O)在-9.57‰～-8.64‰间。结果表明:焉耆盆地内地下水和地表水同源于山区的降水和冰雪融水,且经历了较强的蒸发作用;地下水与地表水之间的直接水力联系较弱,深层地下水主要接受开都河水在洪积扇区的入渗补给,浅层地下水主要接受河流引水灌溉入渗;不同深度地下水之间的水力联系较为密切,为统一的地下水系统。

Features of Environmental Isotopes of Hydrogen and Oxygen of Water and Their Indication in Yanqi Basin, China

Based on the environmental isotope features of hydrogen and oxygen and deuterium excess (d) of groundwater and Kaidu River in Yanqi Basin, this paper analyses the spatial characteristics of δD、δ~(18)O and d in different water,which may indicate the main sources of groundwater and the interaction between groundwater and Kaidu River according to the δD vs. δ~(18) O graph. The δD varies from - 87.60‰ to-61.82‰ and the δ~(18) O, from -10.90‰ to -9.73‰ in groundwater. While the δD ranges from-71.95‰ to -58.58‰ and the δ~(18)O, from -9.57‰ to -8.64‰ in stream water. The results indicate that the groundwater and stream water are mainly derived from the snow melting water and rainfall, and the source water is evaporated a long time before the water infiltration to the groundwater. There is a leak interaction between groundwater and surface water. The groundwater in deep aquifer is mainly recharged by the intensive infiltration of stream water in the proluvial fan, and the groundwater in shallow aquifer mainly derives from irrigation water derived from Kaidu River in plain area. The groundwater in porous Quaternary formation can be regarded as one whole groundwater system because of the close interaction between groundwater and surface water.