松花江吉林段傍河地带地下水化学特征及成因

Chemical characteristics and causes of riparian groundwater in Jilin section of Songhua River

为了解吉林省松花江流域傍河区地下水化学现状,采用数理统计、主成分分析法、Piper三线图示法、离子比例系数法及Gibbs图解法,探究区域地下水化学组分特征及成因。结果表明:研究区地下水属于淡水,长白山区地下水主要受大气降雨和碳酸盐、硅铝酸盐溶滤作用影响,优势离子为Ca^(2+)、Mg^(2+)、HCO_3^-、SO_4^(2-),形成HCO_3+SO_4-Ca+Mg型水,在岩石风化及蒸发浓缩双重作用下,地下水化学类型向SO_4+Cl-Na+Ca和SO_4+Cl-Ca+Mg转化;农安县以西及饮马河、伊通河流域地下水在蒸发浓缩、阳离子交替吸附及地表水混合作用下,Na^+(K^+)、Cl^-成为优势离子,水化学类型向着HCO_3+Cl-Na+Ca方向演变;研究区地下水主要污染组分为来源于工农业及生活污水排放的NO_2^-、总Cr、Fe和PO_4^(3-),同时沿流向耗氧量、NO_2^-等组分超标的地表水对地下水质量影响较大。

In order to evaluate the present situation of the riparian groundwater in Jilin section of Songhua River,we analyzed its hydrochemical characteristics and causes by mathematical statistics,principal component analysis,piper diagram,ion proportional coefficient and Gibbs graphic method. The results show that groundwater in the study area is fresh water. Groundwater in the Changbai Mountain area is mainly affected by atmospheric rainfall,carbonate and aluminosilicate lixiviation,Ca^2＋、Mg^2＋、HCO3^-、SO4^2- are the dominated ions,and the hydro-chemical type is HCO3＋ SO4-Ca＋ Mg. Under the coupled actions of rock weathering and evaporation concentration,the hydro-chemical type gradually transfers to SO4＋ Cl-Na ＋ Ca and SO4＋ Cl-Ca ＋ Mg. Under the influence of evaporation concentration,cation alternate adsorption and surface water mixing,the Na＋（ K＋） and Cl-become the dominated ions of groundwater in the west of the Nongan County and the tributary drainage basin,Yitong River,and the hydro-chemical type transfers to HCO3＋ Cl-Na ＋ Ca. The main pollutants in the study area are NO2^-,total Cr,Fe and PO4^3- from industrial,agricultural and domestic sewage. At the same time,the surface water with the excessive amount of oxygen consumption and NO2^- and other components has great influence on the quality of groundwater.