对丰水期黄河中下游的水化学组成进行调查分析,分析了其水化学特征及主要控制因素。结果 表明:小浪底库区主要水化学类型表现为HCO-3—Cl-—Na+型水。水化学指标的空间分布上,小浪底库区总溶解性固体(TDS)和HCO-3浓度表现出底层显著高于表层的现象(p-3,Ca2+和Mg2+浓度由库区上游(风陵渡断面)至下游(东营断面)不断增加。根据Gibbs图、阴阳离子三角图和离子比值图分析结果,风陵渡断面至东营断面水化学组分主要受流域蒸发盐岩溶解及碳酸盐岩风化影响; 沿岸灌溉回水、生活污水或工业废水等也是影响水体水化学组分的重要原因。主成分分析结果表明,蒸发盐岩溶解、碳酸盐岩风化对水化学组成贡献率分别约为46.55%,35.90%。
The hydrochemical composition of the middle and lower reaches of the Yellow River in the wet season was investigated and the main control factors were discussed. The results show that the main hydrochemical coposition in Xiaolangdi reservoir area is HCO-3—Cl-—Na+, the total dissolved solids(TDS)and HCO-3 concentrations in the Xiaolangdi reservoir area are significantly higher in the bottom layer than those of the surface layer (p-3, Ca2+ and Mg2+ are increasing from the upper reaches(the section of Fenglingdu)to the downstream(the section of Dongying)due to the downstream carbonate rock weathering. The Gibbs diagram, the anion-cation triangle diagram and the ion ratio map showed that the hydrochemical composition of the section of Fenglingdu to the section of Dongying is mainly affected by the dissolution of the evaporite salt rock and the weathering of the carbonate rock. Domestic sewage or industrial wastewater is also an important contribution to the hydrochemical composition. The results of principal component analysis show that the contribution rates of evaporation salt rock dissolution and carbonate rock weathering to hydrochemical composition are 46.55% and 35.90%, respectively.
