全国地下水质分布及变化特征

Distribution and evolution characteristics of national groundwater quality from 2013 to 2017

以2013—2017年地下水监测站点水质监测数据为基础,统计地下水质监测指标的变化特征,筛查影响地下水质的主要指标,研究地下水质变化规律。选取2013—2017年具备连续监测数据的地下水监测井,对常规20项监测指标进行分析。研究发现:就监测站点水质指标而言,总硬度、铁、锰、“三氮”等超标率均达到了10%及以上,是导致地下水水质恶化的主要指标。总硬度超标集中在华北、东北、西南和西北地区的监测井,超标率在各省市间差别较大。氨氮超标率在各省市地区的监测井中差别较大,超标较为严重的省份是黑龙江、江苏、广东和宁夏。硝酸盐氮超标率年际变化稳定,华北、东北和西北地区的监测井中硝酸盐氮超标较为严重。亚硝酸盐氮超标在华北、东北和西北,以及上海、江苏、湖北、广西和贵州的监测井中较为严重。铁、锰超标主要集中在华北、华东、中南地区的监测井中,东三省、安徽、湖北、四川、宁夏等省份尤其严重。基于地下水监测井统计数据,在全国尺度上对地下水质量进行了综合分析评价,总结出了地下水监测中需要着重关注的指标,如“三氮”总硬度,铁、锰等。

Based on the national groundwater quality monitoring data from 2013 to 2017,the variation characteristics of groundwater monitoring indicators are statistically analyzed,the main groundwater indicators based on the national grade groundwater monitoring wells that affecting groundwater quality are investigated,and the variations of groundwater quality from 2013 to 2017 are discussed.20 groundwater items are selected according to the Quality Standard for Groundwater(GB/T 14848—93).The results show that total hardness,total iron,manganese,ammonium,nitrate and nitrite are the main contaminants that caused the deterioration of groundwater quality,and their over stand rate all exceeds 10%.The pollution of total hardness mainly in the North China,Northeast China,Southwest China and Northwest China,the variation of total hardness among the provinces in China is quite large.The ammonium contamination varies greatly among the provinces,and the contamination mainly in the provinces of Heilongjiang,Jiangsu,Guangdong and Ningxia.The nitrate contamination is stable at an annual rate,which are mainly in North China,Northeast China and Northwest China.Nitrite nitrogen pollution is more serious in North China,Northeast China and Northwest China,as well as in Shanghai,Jiangsu,Hubei,Guangxi and Guizhou.Iron and manganese contamination is mainly in North China,East China,and Central South China,and the provinces of Heilongjiang,Jilin,Liaoning,Anhui,Hubei,Sichuan and Ningxia,which are particularly serious.Based on data from the national grade groundwater monitoring wells,this paper makes a comprehensive analysis and evaluation of groundwater quality on a national scale,and summarizes the pollution items that need to be noticed in future groundwater monitoring.