鄂尔多斯白垩系地下水盆地地下水水化学类型的分布规律

在对鄂尔多斯白垩系地下水盆地1 125件地下水化学样品进行分析的基础上，总结出研究区不同循环深度地下水化学类型的分布规律。总体上，盆地北区大致以安边—四十里梁—东胜梁地表分水岭为界，东侧地区的浅层、中层和深层地下水化学类型均以HCO₃型水为主，地下水水平分带不典型；而分水岭以西的摩林河－盐海子地下水系统和都思兔河—盐池地下水系统中，包括浅层、中层和深层在内的各层地下水表现为沿地下水流向，向盆地北、西侧边界，水化学类型具有明显的水平分带规律。而盆地南区地下水分层径流明显，水化学类型复杂，总体上存在一个以定边—环县—合水—华池—吴旗—定边为中心的北部由北向南、东部由东向西、南部由西南向东北的水平分带。

Distribution Law of Groundwater Hydrochemical Type in the Ordos Cretaceous Artesian Basin

The horizontal zonal characteristics of hydrochemical type in groundwater with three circulation depths of shallow,middle and deep level have been studied in the Ordos Cretaceous Artesian Basin on the basis of analyzing 1 125 hydrochemical samples.On the whole,in the north of the basin,the hydrochemical type is mainly HCO3 with atypical horizontal zonal characteristic in shallow,middle and deep groundwater in east of Anbian-Sishiliang-Dongshengliang beam.While the hydrochemical types have a typical zonal characteristic along flow direction of groundwater in shallow,middle and deep groundwater of Molin River-Yanhaizi groundwater regime and Dusitu River-Yanchi groundwater regime.In the south of the basin,groundwater flows hierachically and the hydrochemical types are complex.The distribution rules are follows: the center rule is DingbianHuan town-Heshui-Huachi-Wuqi-Dingbian,while the north rule is from the south to the north,the east rule is from the west to the east, and the south rule is from the southwest to the northeast.