红层丘陵区浅层地下水水化学特征及水质评价

Hydrochemical Characteristics and Water Quality Evaluation of Shallow Groundwater in Red-Layer Area

以遂宁市红层丘陵区浅层地下水为研究对象,利用水样检测结果,结合经典统计学、Piper三线图、单项指标法、等值线图等多种方法,对该区浅层地下水水化学特征及水质和成因进行分析。结果表明,浅层地下水水化学参数Ca^2+、Na^+、HCO3^-、SO4^2-占优势,水体为弱酸至弱碱性的淡水;区内水化学类型主要有6类,其中HCO 3^-Ca型分布最广;水质评价Ⅰ、Ⅱ类水占17.24%,Ⅲ类水占37.24%,Ⅳ、Ⅴ类水占45.52%,但均符合饮用水水质标准;Fe、Mn、NO2^-、NO3^-等4项是影响该区地下水水质的主要指标,而原生地球化学环境和废水污水的人为排放是引起这些指标超标的主要原因。

Taking the shallow groundwater in the red-layered hilly area of Suining City as research object,and the hydrochemical characteristics and water quality of shallow groundwater in the area and the causes are analyzed by using the sample test results combining the methods of classic statistics,three-line map of Piper,single indicator and isometric line map.The results show that,(a)the chemical parameters of Ca 2+,Na+,HCO-3 and SO 2-4 are dominant in shallow groundwater,and the water body is weak acid to weakalkaline fresh water;(b)there are six types of water chemistry in the region,of which,the HCO 3-Ca type is the most widely distributed;(c)the water quality evaluation shows that the Class I and II water accounts for 17.24%,Class III water accounts for 37.24%and Class IV and V water accounts for 45.52%,but all of them meet the standards of drinking water quality;and(d)the Fe,Mn,NO-2 and NO-3 are the main indicators affecting the groundwater quality in this area,while the protogeochemical environment and the anthropogenic discharge of wastewater are the main causes of these indicators exceeding the standard.