克鲁伦河流域下游水体氢氧同位素与水化学特征

Hydrochemical and hydrogen and oxygen isotopic characteristics of water in the low reach of Kherlen River

通过对克鲁伦河流域下游河水与地下水的主要离子水化学与氢氧同位素进行分析,结合区域水文地质资料,利用Durov图、空间插值、统计分析等方法分析了河水与地下水水化学与氢氧同位素特征。结果表明,河水的水化学类型主要为Na-Ca-HCO3型,地下水水化学类型为Na-Cl和Ca-Na-HCO3型。克鲁伦河水主要离子浓度与氢氧同位素空间分布特征显著较地下水稳定、空间差异小。流域内地下水与地表水主要来自降水补给,地下水也是克鲁伦河的主要补给源。氘盈余变化揭示出克鲁伦河水的蒸发分馏程度强于地下水,除流域内水体蒸发主要受地质地貌影响外,人类活动对河水的影响显著于周边地下水。G3点所在的西庙为一个完整独立的水文地质单元,其表现出的水化学与氢氧同位素特征均异于其他地下水。流域内部分地下水F-含量超标,虽然一定程度是受人类活动影响,但更多的是基于综合水文地质条件基础上的自然现象,已严重威胁人类生存,应引起当地有关部门的高度重视,避免氟中毒事件重现。

The Kherlen River is the main river flowing into Hulun Lake,the largest lake in the north of China,and it is located in Hulun Buir Grassland as a typical grassland river. The Kherlen River originates from the south of Kent Mountain in Mongolia and flows from west to east. The Kherlen River has a total length of 1 264 km,with206. 44 km in China,and it has a total drainage area of 7 153 km2. Combining with the regional hydrogeological data,the characteristics of the hydrochemistry and hydrogen and oxygen isotopes of the main ions in the river water and underground water in the low reach of Kherlen River were analyzed with the Durov diagram,spatial interpolation and statistical analysis method. The results show that the hydrochemical types of the river water are mainly Na-Ca-HCO3 type,and the hydrochemical types of underground water are Na-Cl and Ca-Na-HCO3. The spatial distribution characteristics of the main ion concentration and hydrogen and oxygen isotope in the Kherlen River water are more stable than the groundwater,and the spatial difference is small. Hydrogen and oxygen isotope relationship indicates the groundwater and surface water were mainly supplied by the precipitation,while the groundwater is the main supply source of Kherlen River. The variation of deuterium surplus reveals that the evaporation and fractionation degree of the Kherlen River is stronger than that of the groundwater. Besides the water evaporation of the basin is mainly influenced by the geology and geomorphology of the region,the influence of the human activities on the river water is much stronger than that on the groundwater. The West Temple at the G3 point is a complete and independent hydrogeological unit,where the characteristics of hydrochemistry and hydrogen and oxygen isotopes are different from other groundwater. The Fl-content of some groundwater in the basin exceeds certain limits,which is caused partially by the human activities to a certain degree but is mainly a naturel result of the comprehensive hydrogeological conditions. This becomes a serious threat to human survival,and the local authorities should pay more attention to this issue and take action to avoid the recurrence of fluorosis.