松嫩平原地下水化学特征

根据新一轮地下水资源调查的水质资料，通过对2000多个地下水样的水质分析结果研究，发现与上世纪80年代相比，松嫩平原地下水化学类型和主要化学组分含量都发生了很大变化，农业污染严重.地下潜水硝酸根平均含量达77.03mg/L，超过Ⅳ级水质标准的样品数量占到26.9%；亚硝酸根平均含量为0.14mg/L，超过Ⅳ级水质标准的样品数量占14.53%.在主要农业区的地下潜水水化学类型中，阴离子出现硝酸型水.

HYDROCHEMISTRY OF THE GROUNDWATER IN SONGNEN PLAIN

The groundwater resources in Songnen Plain are significant for the local economic development.Based on the data from the new round of groundwater survey,the author studied the result of analysis on the quality of groundwater samples.It is concluded that,comparing those in 1980s,the chemical types and compositions of the groundwater in Songnen Plain have changed a lot.Agricultural pollution of the groundwater is quite serious.According to the National Quality Standard for Groundwater(GB/T14848-93),the ratio of samples that surpass the Grade IV standard of NO3-content in water is up to 26.9%,with 77.03 mg/L averagely;while the ratio for NO2-is up to 18.1%,with 0.14 mg/L averagely.In the main agriculture area,the NO3--type of water occurs,which was rarely seen in the result of the groundwater survey in 1980s.