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2014年8月对拉市海表层及不同深度湖水进行采样,分析拉市海湖水的氢氧稳定同位素的空间变化及其影响因素,探讨典型温冰川区域湖泊的水文补给特征.结果表明,拉市海表层湖水的δ~(18)O、δD值分别在-12.98‰~8.16‰和-99.42‰~-73.78‰之间波动,平均值分别为-9.75‰和-82.23‰;表层湖水的δ~(18)O及过量氘表现出相反的空间变化特征,有河水注入的区域δ~(18)O值较低而过量氘值较高;垂直方向上过量氘随深度变化较小,表明湖水在垂直方向上混合较充分,不同深度层上过量氘表现出自东向西先增大后减小的变化趋势,这可能与入湖河流的分布、湖泊所处的地理位置及自然条件等密切相关;同位素对比研究发现,拉市海的主要补给源为大气降水及河水,冰雪融水可能间接补给拉市海;对拉市海与青藏高原地区典型湖泊和非冰川区湖泊的氧同位素组成对比发现,冰川区湖泊中稳定同位素表现出明显的高程效应(拉市海除外),δ~(18)O随海拔升高而降低.非冰川区湖泊蒸发效应较为明显,同位素值明显偏正.
In August 2014, the surface water samples of Lashihai Lake and different depths were sampled to analyze the spatial and temporal variations of H and O stable isotopes in Lashihai Lake and the influencing factors, and to investigate the hydrological recharge characteristics of typical warm glaciers. The results show that, The δ ~ (18) O and δD values of sea surface water fluctuated between -12.98 ‰ and 8.16 ‰ and -99.42 ‰ ~ -73.78 ‰, respectively, and the average values were -9.75 ‰ and -82.23 ‰, respectively. The δ ~ (18) O and excess deuterium show the opposite spatial variation characteristics, δ ~ (18) O values are lower and excessive excess deuterium values are higher in the areas injected with river water; the excess deuterium in the vertical direction is smaller with depth, In the vertical direction, the deuterium shows a tendency of increasing firstly and then decreasing from east to west, which may be closely related to the distribution of rivers in rivers, the geographical location and natural conditions of lakes; Isotope comparison study found that the main recharge source for Lashihai is atmospheric precipitation and river water, and snowmelt melt may indirectly supply Lashihai. Comparing the oxygen isotopic compositions of lakes in the Lashihai with the typical and non-glacial lakes in the Tibetan Plateau, Glacier stable in the lake Isotope effect showed significant elevation (except Lashihai), δ ~ (18) O decreases with increasing altitude. Glacier lakes of evaporation of the non-obvious, evident isotope prejudiced.