巴丹吉林沙漠腹地湖泊的水化学特征及其全新世以来的演变

WATER CHEMISTRY OF THE LAKES IN THE BADAIN JARAN DESERT AND THEIR HOLOCENE EVOLUTIONS

本文阐述了巴丹吉林沙漠丘间地湖泊及其周围浅层地下水的水化学特征。在研究地区湖泊中的TDS变化范围较大 ,介于 1 .2g/L和 3 98.2g/L之间。微咸湖泊属于Na (Ca) (Mg) Cl (SO4) (HCO3)类型 ,而含盐量高的湖泊则属于Na (K) Cl (CO3) (SO4)类型。文章根据同位素分析结果 ,提出了浅层地下水年龄都较年轻的观点。结合对古湖岸地貌与沉积的研究 ,文章还指出巴丹吉林沙漠地区湖泊在全新世发生过明显变化 ,湖水矿化度的增高和水域面积的快速萎缩是由于全新世中期以来出现的干旱化所造成的。

The author describes the water chemistries of lakes and shallow groundwater in the Badain Jaran Desert located in the western Inner Mongolia of China. In the studied lakes,the totally dissolved solids (TDS) change from 1.2 g/L to 398.2 g/L. These lakes can be divided into two main types: the brackish ones with ions Na (Ca) (Mg) Cl (SO 4) (HCO 3),and the lakes with high salinities showing ion spectrum Na (K) Cl (CO 3) (SO 4). On the basis of isotope analysis it is pointed out that the ages of the shallow groundwater are quite young in general. By examining the palaeo shores of lakes and lacustrine deposits,it is concluded that the lakes have been exposed to dramatic changes during the Holocene. It is found out that the increase of salinities and the decrease of water table have originated from a climatic aridification having occurred since middle Holocene.