内蒙古河套平原高矿化咸水分布规律及成因分析

Distribution characteristics and formation of high mineralized saline groundwater in Hetao Plain,Inner Mongolia

河套平原地下高矿化咸水分布广泛,使得河套地区土壤盐渍化、沙漠化等环境问题突出。因此针对河套平原高矿化咸水水化学类型、分布特征、成因机理进行了调查研究。研究表明:河套平原受地质、氧化、还原因子影响,表现出21种水化学类型,主要以Na+Ca+Mg-HCO_3+SO_4+Cl和Na+Mg-HCO_3+SO_4+Cl型水为主;河套平原地下水呈现出明显的水平分带规律,自西向东由北向南可分出5条高矿化水分布带;高矿化带离子成分主要来源于蒸发-浓缩作用,主要受气候、沉积环境、水文地质条件等因素的影响,而后套平原扇前洼地、黄河北岸和西山嘴高矿化水分布带的地下水则受深层海相沉积地下水的影响。研究结果可为区域水资源合理配置,促进水资源开发利用提供科学依据。

The high mineralized saline groundwater is widely distributed in the Hetao Plain, which make the soil salinization, desertification and other environmental problems prominent. Therefore, we investigate and analyze the hydrochemical type, distri- bution and formation mechanism of the high mineralized saline water in the Hetao Plain. The results show that the high mineral- ized saline water in Hetao Plain is affected by geology, oxidation and reduction factors and has 21 kinds of hydrochemical types, the main types are Na ＋ Ca ＋ Mg - HC03 ＋ SO4 ＋ C1 and Na ＋ Mg - HCO3 ＋ SO4 ＋ C1; the distribution of high mineralized saline water has some relationship with the distribution of high arsenic and shows obvious horizontal zoning rule, i. e. , 5 high mineral- ized water distribution belts from the west to the east and from the north to the south ; the ionic components of the high mineralized belt are mainly derived from the evaporation and concentration effect, which may be mainly influenced by climate, sedimentary environment, hydro - geological and hydrological conditions ; the high mineralized saline groundwater in the front of the Houtao plain fan, the area north to the Yellow River and Xishanzui area of the Houtao plain are affected by deeper groundwater formed in deep marine deposits. The results can provide a scientific basis for the rational allocation of regional water resources and utiliza- tion of water resources