南襄盆地地下水污染对水化学类型变化的指示意义

地下水水化学分类是按一定的规则将地下水中的化学成分归类,是认识地下水形成的重要途径。然而,在地下水受污染的条件下,污染质将成为地下水化学组分的一部分,指示着区域地下水化学类型受污染质影响。针对该问题采用了在舒卡列夫分类法中加入NO_3~-指标的方法,发现计入NO_3~-后水化学命名发生改变的点占17.2%,水化学类型新增了NO_3、Cl·NO_3、HCO_3·NO_3型水3种;原舒卡列夫分类中HCO_3型水所占面积略有增加,其它3种水化学类型面积有所减少。常规水化学分类法主要用于判断地下水的自然成因,而人类活动使浅层地下水的原生环境发生了较大变化,在进行与人为污染组分有关的地下水化学分类工作时,并不适用。因此,水化学分类中计入NO_3~-这一典型污染指示因子,有助于从污染角度研究地下水。

Indicative Significance of Groundwater Pollution on Variation of HydrochemicalTypes in Nanxiang Basin

The chemical classification of groundwater is an important way to recognize the formation of groundwater by classifying chemical constituents in groundwater according to the relevant rules. However, the pollutant will become the part of the chemical composition of groundwater under the condition of groundwater pollution. This paper applied the method of adding N03'' to the Shukalev classification. The study show that the changes in hydrochemical nomenclature have made up for 17.2% since NO3'' was taken into account. The hydrochemical types of N03, C1*N03 and HC03 * N03 have been added. The area of HC03 type increase slightly in the original Schukalev classification while the others decrease. The conventional hydrochemical classification is mainly adapted to judge the natural causes of groundwater, but it is not adaptable for the chemical classification of groundwater which is related to man -made pollution components because the human activities greatly contribute the original environment of shallow groundwater change. Therefore, NO3'' prompts the groundwater pollution research of the hydrochemical classification.