【摘要】 民勤盆地地下水化学特征具有明显的水平与垂直分带特征 ,沿水流方向 ,自西南的SO42 --Na+ -Mg2 + 型逐渐过渡为Cl--SO42 --Na+ 型 ,湖区浅层水则完全为Cl--Na+ 型水。垂直向上表现为上咸下淡的趋势。随着进入盆地地表水量的减少与地下水开采量逐年增大 ,地下水环境日益恶化 ,咸水入侵深度达 6 0m ,TDS普遍增高。特别是湖区局部浅层地下水矿化度 ,由 2 0世纪 70年代的 3g/L发展到现在的 16g/L。据此 ,增加淡水资源和减少地下水的超采量 ,发展节水高效农业是保护该盆地地下水环境的最基本措施。更多还原

【Abstract】 The total area of the Minqin Basin is 1.6×104 km2, but the area of the oasis occupies 9% only and is gradually reduced due to the shortage of water resources. Along with the population growth and the economic development, groundwater in the basin is excessively pumped, thus the groundwater quality is seriously deteriorated. In this paper, the change of the groundwater environment and its causes in the basin are researched. The results show that the chemical properties of groundwater in the Minqin Basin are obviously characterized by the horizontal and vertical zonal distribution. Along the direction of stream flow, the groundwater changes gradually from the SO 4 2--Na+-Mg 2+ pattern in the south to the Cl--SO 4 2--Na+ pattern, and the shallow groundwater in the dried-up Qingtu Lake area becomes completely the Cl-Na pattern. Vertically, the shallow groundwater is salty and the deep groundwater is fresh. Along with the sharp reduction of surface water and the seriously excessive pumping of groundwater, the groundwater environment is seriously deteriorated, and the infiltration depth of salty water is down to 60 m. Especially, the mineralization of shallow groundwater in the dried-up Qingtu Lake area is increased from 3 g/L in the 1970’s to 16 g/L at present. Therefore, it is the radical measure for conserving the groundwater environment in the basin to increase the surface water resources, reduce the volume of pumped groundwater, and develop the water-saving agriculture.更多还原