济南趵突泉泉域岩溶水化学特征时空差异性研究

Spatiotemporal difference study of karst hydrochemical characteristics in the Baotu Spring area of Jinan

水文地球化学一直是水文地质领域的研究重点,而地下水化学组分的时空变化特征受多种因素的影响。为了掌握济南趵突泉泉域岩溶地下水水化学特征时空差异性,本文分别于枯、丰水期在泉域内采集并分析了岩溶地下水样品,并采用数理统计、Piper三线图、Gibbs图解法及离子比例系数法等分析手段,对研究区岩溶地下水水化学特征及时空差异性进行了研究。结果显示,研究区地下水优势阳离子为Ca,优势阴离子为HCO3,丰水期除HCO3外,其他离子的变异系数较枯水期普遍升高,且大于0.5,表现出丰水期空间差异性增大的特点。地下水水化学类型具有以HCO3·SO4-Ca为主,多种类型并存的特点。Ca、Mg、HCO3含量在枯、丰水期比值要小于1,且比其他离子要相对稳定,呈现出全局性特点。而Na、K含量在枯、丰水期比值波动较大,大部分比值大于1,Cl、SO4、NO3含量在枯、丰水期比值具有波动剧烈的特点,呈现出区域性特征,同时表明人类活动大大改变了研究区地下水水化学场的分布特征。

Hydrogeochemistry has long been the research focus in the field of hydrogeology.But temporal and spatial variation characteristics of groundwater chemical components are affected by many factors.In this paper,karst groundwater sampling sites were arranged in Baotu spring hydrogeological unit to collect karst groundwater samples in dry and rainy season in order to research spatiotemporal difference of karst groundwater hydrochemical characteristics by mathematical statistics,correlation analysis,Piper diagram,Gibbs diagram and ion proportional coefficient method.The results show that the dominant cation in groundwater is Ca and the dominant anion is HCO3.The variation coefficients of other ions(greater than0.5)in rainy season are generally higher than that of dry season expect HCO3,which indicates increasing of spatial difference during rainy season.Groundwater types are mainly HCO3·SO4-Ca coexisting with many types.Ratios of Ca,Mg and HCO3 contents are less than one during dry and rainy season and are stable than other ions,presenting an integrated feature.Na and K contents fluctuate greatly during dry and rainy season with their ratio more than one.Cl,SO4 and NO3 contents have a characteristic that the ratio fluctuates greatly in dry and rainy season,presenting regional features.These characteristics of spatiotemporal difference indicates that human activities have greatly changed the distribution pattern of groundwater chemical field in the study area.