三江平原富锦地区浅层地下水水化学特征及其形成作用

Hydrochemical Characteristics and Formation of the Shallow Groundwater in Fujin,Sanjiang Plain

三江平原富锦地区是我国重要的产粮基地,农业灌溉对当地地下水水质造成了一定程度的影响,而地下水水质的变化制约着当地农业的发展及居民的饮水安全,因此对三江平原富锦地区地下水水化学特征及其形成作用进行研究具有十分重要的意义。本次研究对浅层地下水及地表水进行采样,运用Gibbs图、离子比例系数、δD和δ^(18)O同位素、克里金插值及反向地球化学模拟等方法,对三江平原富锦地区浅层地下水的水化学形成机制进行了分析。研究结果表明:地下水中TDS、NO_3-N质量浓度沿地下水流向呈递增趋势,地下水水化学类型以HCO_3-Ca和SO_4-Ca为主;硅铝酸盐以及岩盐的风化溶解是研究区地下水中离子的主要来源;溶滤作用、阳离子交替吸附作用和农业施肥、地下水开采等人类活动影响是控制地下水化学特征形成的主要作用。

Fujin,in Sanjiang Plain,is an important grain base in China.The agriculture irrigation caused the deterioration of groundwater quality.The groundwater quality further more restricted the development of local agriculture and posed a threat to the safety of drinking water.Therefore,it is significant to study the hydrogeochemical characteristics and formation groundwater in Fujin,Sanjiang Plain.In this study,46 samples were collected,including 35 groundwater samples and 11 surface water samples.The multiform methods of Gibbs figure,ionic ratios,Kriging and inverse hydrogeochemicalmodeling were applied in order to analyze the formation mechanism of groundwater hydrogeochemistry.The results show that：the concentrations of TDS and NO3-N in groundwater increased along the flow;the hydrochemical type of groundwater is mainly HCO3-Ca and SO4-Ca;the hydrochemical components in groundwater came mainly from the weathering dissolutions of aluminosilicate and halite leaching,cation exchanges and human activities,such as fertilization,groundwater pumping,are the main processes controlling the formation of groundwater hydrochemistry.