东寨港流域地表水水化学组成特征及其成因

Hydrochemical Characteristics and Genesis of Surface Water in Dongzhai Harbor Watershed

为研究滨海地区地表水资源和红树林生态系统的水环境,利用水化学分析、数理统计和Gibbs水-岩分析模型等方法对东寨港流域内演丰西河和三江河两条河流水体的水化学组成和氢氧稳定同位素特征进行分析,揭示了演丰西河和三江河河流地表水的水化学组成特征,讨论了该区域地表水的水化学组分变化及其控制因素。结果表明:演丰西河地表水的水化学类型以Na-Cl型为主,三江河地表水的水化学类型从Na·Ca-Cl·HCO;型转变为Na-Cl型;演丰西河和三江河河流地表水的水化学组成特征均主要受蒸发结晶和岩石风化作用的控制,而海水潮汐混合作用和红树植物的生理功能使演丰西河流域的蒸发作用更强烈,岩石风化作用则对三江河地表水水化学类型的影响较大;对演丰西河和三江河地表水体中氢氧同位素分析显示,两条河流的主要补给来源均为大气降水,且均受到二次蒸发作用的影响;海水潮汐混合作用对演丰西河地表水水化学组成的影响较大。

In order to study the surface water resources in coastal areas and the water environment of the mangrove ecosystem, using the hydrochemical analysis, mathematical statistics and Gibbs water-rock analysis model, this paper analyzes the hydrochemical compositions and hydrogen-oxygen stable isotope characteristics of Yanfengxi River and Sanjiang River in Dongzhai Harbor.The paper reveals the hydrochemical characteristics of Yanfengxi River and Sanjiang River and discusses the hydrochemical changes and controlling factors of the surface water in this region.The results show that the chemical type of Yanfengxi River is mainly Na-Cl type, and Sanjiang River changes from Na·Ca-Cl·HCO;type to Na-Cl type.The hydrochemical characteristics of surface water in both Yanfengxi River and Sanjiang River are mainly controlled by evaporation crystallization and rock weathering, while the evaporation of Yanfengxi River is more intense due to seawater tidal mixing and physiological functions of mangrove plants, while rock weathering has a greater influence on the water chemical types of Sanjiang River.The hydrogen and oxygen isotopic analysis shows that the main recharge sources of surface water in the two rivers are atmospheric precipitation, and both are affected by secondary evaporation.Sea tidal mixing has a great influence on the water chemical composition of yanfengxi River.