黄河三角洲浅层地下水化学特征与演化

Research on the variation and evolution of groundwater chemistry in the Yellow River Delta

2009年4月～2010年3月连续2年对黄河三角洲19口地下水监测井进行观测并对地下水离子化学成分分析，探讨了该区域浅层地下水化学成分、水化学类型及演化规律，为揭示区域地下水环境特征和演化具有现实意义。结果表明，黄河三角洲地区地下水pH值变化较小，地下水埋深较浅且年内变化幅度为1．0～3．0m，但矿化度和各离子差异明显，地下水以Na＋、cl-占绝对优势；矿化度较低的测井的离子浓度变幅较小，反之，矿化度高的测井离子浓度变幅较大；地下水化学类型分为氯化物型、重碳酸盐氯化物型、重碳酸盐氯化物硫酸盐型和硫酸盐重碳酸盐型四大类型，主要包括Na＋．C1-、Na＋．C1-．Hco；、Na＋．C1-．Hcoi、Na＋-CI-．Hcoi．sol-、Na＋．Hcoi．C1-．SO2,-和Na＋-SO2＋Hcoi六种子类型，氯化物型主要分布于广饶县成水入侵区和滨海区域，重碳酸盐氯化物型主要分布于黄河三角洲保护区内，重碳酸盐氯化物硫酸盐型分布在广饶县咸水入侵区，硫酸盐重碳酸盐型主要分布在靠近黄河流路附近；根据黄河三角洲流路变迁和Gibbs模型，黄河三角洲地区水样化学组成均落在Gibbs提出的BoomerangEnvelope模型右上翼，表明研究区水样化学组成主要受蒸发和沉淀作用，海水控制起次要作用，土地利用变化、灌溉、施肥等人为活动的影响亦不能忽视。

The chemical composition, hydrochemical type and evolution rule of the groundwater in the Yellow River Delta were analyzed through two years continuous observation of the 19 groundwater monitoring wells in the Yellow River Delta. The results show that the pH change of groundwater in the Yellow River Delta is small; the groundwater depth is shallow and the yearly range is 1.0 to 3.0 m, however the salinity and the difference of ions are obvious. The groundwater is mainly composed with Na＋ and C1-. The range of ion concentration of low salinity is small. On the other hand, the range of ion concentration of high salinity is large. The chemical types of ground- water can be divided into type of chloride, bicarbonate, chloride, bicarbonate, chloride sulfate and sulfate bicarbon- ate. It mainly includes the Na＋-C1-, Na＋-C1-. HCO-3, Na＋-C1-. HCO3, Na＋-CI-. HCO3. SO2-, Na＋- HCO3 .C1-. SO2- and Na＋- SO2-. HCO3. The chloride type is mainly distributed in saltwater intrusion area and coastal area of Guangrao County; the carbonate chloride type is mainly distributed in the Yellow River Delta pro- tection area; the bicarbonate chloride sulfate type is mainly distribution in salt-water intrusion zone of Guangrao County; sulfate bicarbonate type is mainly distributed close to the Yellow River flow. According to the changes of flow of the Yellow River Delta and Gibbs models, the chemical composition of the water in the Yellow River Delta both falls in the upper wing of Gibbs Boomerang Envelope model. In conclusion, all of that indicate that water chemical composition in the study area is mainly controlled by the action of water. The evaporation and deposition play a secondary role. The impact of human activity such as land use change, irrigation, fertilization also cannot be ignored.