基于正定矩阵因子分析模型的滹沱河冲洪积扇地下水污染源解析

Source analysis of groundwater pollution in Hutuo River alluvial-pluvial fan based on positive matrix factorization model

于2017年9月采集了33组地下水水样,运用衬度系数方差和正定矩阵因子分析(PMF)模型研究了滹沱河冲洪积扇地下水的水化学特征及控制因素,并解析主要污染来源。结果表明:(1)地下水中总硬度(TH)和NO-3超标严重,NO-3为5.0~326.2 mg/L,沟谷平原区、冲洪积扇顶部和冲洪积扇中部超标率分别为55.6%、21.4%和30.0%;TH为140~833 mg/L,沟谷平原区、冲洪积扇顶部和冲洪积扇中部超标率高达77.8%、64.3%和60.0%。该地区地下水已受到了人类活动的显著影响。(2)岩石风化是地下水水化学的主要控制因素,地下水主要的水化学类型是HCO_(3)·SO_(4)-Ca和HCO_(3)·SO_(4)-Ca·Mg。(3)冲洪积扇顶部各组分衬度系数方差整体要大于沟谷平原区和冲洪积扇中部,冲洪积扇顶部内地下水受人类活动影响强烈。(4)PMF源解析结果表明,该地区地下水主要污染源是生活污水和化肥、工业污染源和地下水超采诱发的水岩交互作用。

33 groundwater samples was collected and determined in September,2017.Variance analysis of contrast coefficient and positive matrix factorization(PMF)model were used to analyze the hydrochemical characteristic of groundwater and factors controlling hydrochemistry,and to identify the main pollution sources of Hutuo River alluvial-pluvial fan region.Results showed that:(1)the rate of exceeding standard of NO-3 and total hardness(TH)were very high.The concentration ranges of NO-3 was 5.0-326.2 mg/L,and the rate of exceeding standard in the valley plain,the top of alluvial-pluvial fan and the center of alluvial-pluvial fan were 55.6%,21.4%and 30.0%,respectively.The concentration ranges of TH was 140-833 mg/L,and the rate of exceeding standard in the valley plain,the top of alluvial-pluvial fan and the center of alluvial-pluvial fan were 77.8%,64.3%and 60.0%,respectively,which indicated that groundwater had been significantly affected by human activities in the area.(2)Rock weathering was the main factor controlling groundwater chemistry in this area and the main types of groundwater chemistry were HCO_(3)·SO_(4)-Ca and HCO_(3)·SO_(4)-Ca·Mg.(3)Variance of contrast coefficient of hydrochemical component in the top of alluvial-pluvial fan were higher than in the valley plain and the center of alluvial-pluvial fan.The groundwater of the top of alluvial-pluvial fan was strongly influenced by human activities.(4)The results of PMF model showed that the main pollution sources of groundwater in this area were domestic sewage and chemical fertilizer,industrial pollution source and the water-rock interaction induced by groundwater overexploitation.