长河流域矿区地表水水化学特征及驱动因子分析

Hydrochemical characteristics and driving factors of surface water in the mining area of Changhe River Basin

为了研究晋城市长河流域采煤区地表水水质情况、查清其水化学特征,明晰其影响因素及主要离子来源。现场采集了地表水水样9组,采用数理统计方法分析水化学特征,运用Piper三线图分析水化学类型,通过Gibbs图和离子相关分析等方法探讨了地表水主要离子的来源及其影响因素。结果表明,研究区地表水TDS为126—604 mg·L^(−1),平均值为344.11 mg·L^(−1);pH值为7.43—8.17,平均值为7.79,属于弱碱性水。地表水阳离子以Ca^(2+)和Mg^(2+)为主,阴离子主要是HCO_(3)^(−),水化学类型为HCO_(3)^(−)Mg。通过主要离子的相关性分析可知,TDS与Na^(+)、K^(+)、HCO_(3)^(−)、SO_(4)^(2)和Cl^(−)都存在显著的正相关性,这些离子对TDS都有贡献。HCO_(3)^(−)与Na^(+)相关,与K^(+)存在显著相关性,可能来源于含钠或钾硅酸盐。通过水岩模型分析可知,研究区地表水水化学成因主要受岩石风化作用控制,多数离子是由硅酸盐岩与碳酸盐岩风化溶解作用,少数阳离子受到水体离子交换作用影响。相关的研究成果可为研究区水资源规划配置提供科学的参考意见。

In order to study the water quality of the surface water in the Changhe coal mining area of Jincheng City,find out its hydrochemical characteristics,and clarify its influencing factors and main ion sources.Nine groups of surface water samples were collected on site,and the hydrochemical characteristics were analyzed by mathematical statistics,the hydrochemical types were analyzed by Piper trigraph,and the sources and influencing factors of main ions in surface water were discussed by Gibbs graph and ion correlation analysis.The results showed that:TDS of surface water in the study area was 126—604 mg·L^(−1),with an average value of 344.11 mg·L^(−1).The pH value is 7.43—8.17,and the average value is 7.79,which belongs to weakly alkaline water.The main cations in surface water are Ca^(2+)and Mg^(2+),the anions are mainly HCO_(3)^(−),and the hydrochemical type is HCO_(3)^(−)Mg.The correlation analysis of major ions shows that TDS is significantly positively correlated with Na^(+),K^(+),HCO_(3)^(−),SO_(4)^(2) and Cl^(-),and these ions all contribute to TDS.HCO_(3)^(−) is associated with Na^(+) and significantly associated with K^(+),and may be derived from sodium or potassium silicates.Through the analysis of the water-rock model,it can be seen that the hydrochemical genesis of the surface water in the study area is mainly controlled by rock weathering,most of the ions are dissolved by the weathering of silicate rock and carbonate rock,and a few cations are affected by water ion exchange.Relevant research results can provide scientific references for water resources planning and allocation in the research area.