Key Laboratory of Ecohydrologyand Integrated River Basin Science, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Donggang West Road No 320, Lanzhou 730000, China.
Ground Water. 2012 Sep-Oct;50(5):715-25. doi: 10.1111/j.1745-6584.2011.00895.x. Epub 2011 Dec 9.
There are many viewpoints about the sources of groundwater in the Badain Jaran Desert (BJD), such as precipitation and snowmelt from the Qilian Mountains (the upper reaches [UR] of the Heihe River Basin [HRB]) and precipitation from the BJD and the Yabulai Mountains. To understand the source of the groundwater of the BJD and their possible associations with nearby bodies of water, we analyzed variations of stable isotope ratios (δD and δ(18) O) and the deuterium excess (d-excess) of groundwater and precipitation in the BJD, of groundwater, precipitation, river and spring water in the UR, and of groundwater and river water in the middle and lower reaches (MR and LR) of the HRB. In addition, the climatic condition under which the groundwater was formed in the BJD was also discussed. We found obvious differences in δD, δ(18) O, and d-excess among groundwater in the BJD, nearby water bodies and the HRB. The groundwater δD-δ(18) O equation for the BJD was δD = 4.509δ(18) O-30.620, with a slope and intercept similar to that of nearby areas (4.856 and -29.574), indicating a strong evaporation effect in the BJD and its surrounding areas. The equation's slope of the BJD was significantly lower than those of HRB groundwater (6.634), HRB river water (6.202), precipitation in the BJD and Youqi (7.841), and the UR of the HRB (7.839). The d-excess (-17.5‰) of the BJD was significantly lower than those of nearby groundwater (-7.4‰), HRB groundwater (12.1‰), precipitation in the BJD (5.7‰) and in the UR of the HRB (15.2‰), and HRB river water (14.4‰). The spatial patterns of δ(18) O and d-excess values in the BJD suggest mixing and exchange of groundwater between the BJD and neighboring regions, but no hydraulic relationship between the BJD groundwater and water from more distant regions except Outer Mongolia, which is north of the BJD. Moreover, we conclude that there is little precipitation recharge to groundwater because of the obvious d-excess difference between groundwater and local precipitation, low precipitation, and high evaporation rates. The abnormally negative d-excess values in groundwater of the BJD indicate that this water was formed in the past under higher relative humidity and lower temperatures than modern values.
巴丹吉林沙漠（BJD）地下水的来源有多种观点，如祁连山（黑河上游流域 [UR]）的降水和融雪以及 BJD 和雅布赖山的降水。为了了解 BJD 地下水的来源及其与附近水体的可能联系，我们分析了 BJD 地下水、UR 地下水、降水、河流水和泉水、HRB 中下游（MR 和 LR）河流水的稳定同位素比值（δD 和 δ(18) O）和氘过剩（d-excess）的变化。此外，还讨论了 BJD 地下水形成时的气候条件。我们发现 BJD 地下水、附近水体和 HRB 之间的 δD、δ(18) O 和 d-excess 存在明显差异。BJD 地下水的 δD-δ(18) O 方程为 δD = 4.509δ(18) O-30.620，斜率和截距与附近地区（4.856 和-29.574）相似，表明 BJD 及其周围地区存在强烈的蒸发效应。BJD 方程的斜率明显低于 HRB 地下水（6.634）、HRB 河水（6.202）、BJD 和右旗（Youqi）降水（7.841）和 HRB UR（7.839）。BJD 的 d-excess（-17.5‰）明显低于附近地下水（-7.4‰）、HRB 地下水（12.1‰）、BJD 降水（5.7‰）和 HRB UR 降水（15.2‰）以及 HRB 河水（14.4‰）。BJD 中 δ(18) O 和 d-excess 值的空间格局表明 BJD 与邻近地区之间地下水的混合和交换，但除了位于 BJD 北部的蒙古国以外，BJD 地下水与更远地区的水之间没有水力联系。此外，我们得出结论，由于地下水与当地降水之间存在明显的 d-excess 差异、降水量低和蒸发率高，因此降水对地下水的补给很少。BJD 地下水异常负的 d-excess 值表明，这种水是在过去相对湿度较高、温度较低的情况下形成的，而现代的相对湿度和温度值都较低。
