干旱地区水循环过程中的地下水化学特征研究——以蒙古国前巴音钼矿水源地为例

Study on the Chemical Characteristics of Groundwater in the Process of Water Cycle in Arid Areas——Taking the water source of the former Bayin molybdenum mine in Mongolia as an example

地下水的水化学类型在径流过程中会不断变化,并在径流与赋存的不同状态下体现出不同特征,体现出不同的地下水运移规律。本文以蒙古国前巴音钼矿水源地为例,选取水源地范围内的19个钻孔水样进行分析,取得了主要阴阳离子、TDS和水化学类型等数据。通过对地下水化学的空间分布特征、TDS值的变化和主要阴阳离子的演化规律进行研究发现:研究区水源地地下水补给来源为大气降水,沟谷东部地区的水循环强度高于西南部地区,外围地区最弱,地下水的水平径流较弱小于垂向;受水循环强度影响沟谷东部形成地矿化度的HCO_3型水,西南部形成HCO_3·Cl·SO_4、HCO_3·SO_4·Cl、HCO_3·SO_4型水,沟谷外围地区形成SO_4·HCO_3·Cl、Cl·SO_4·HCO_3、SO_4·HCO_3、Cl·SO_4型水,干旱地区水循环强度和补径排条件的差异会形成不同的水化学类。

The water chemistry type of groundwater will change constantly during the runoff process,and it will show different characteristics under different states of runoff and occurrence,reflecting different groundwater migration laws.Taking the water source of the former Bayin molybdenum mine in Mongolia as an example,19 water samples from the water source area were selected for analysis,and the main anions and cations,TDS and water chemistry types were obtained.Through the study of the spatial distribution characteristics of groundwater chemistry,the change of TDS value and the evolution law of main anion and cation,it is found that the source of groundwater recharge in the water source area of the study area is atmospheric precipitation,and the water circulation intensity in the eastern part of the valley is higher than that in the southwest.Weak,the horizontal runoff of groundwater is weaker than the vertical direction;the HCO3 type water which affects the salinity of the eastern part of the valley due to the intensity of the water circulation,and the HCO3·Cl·SO4,HCO3·SO4·Cl,HCO3·SO4 type water in the southwest,the valley SO4·HCO3·Cl,Cl·SO4·HCO3,SO4·HCO3,Cl·SO4 type water is formed in the peripheral areas,and the difference in water cycle intensity and fill-discharge conditions in arid areas will result in different water chemistry.