淮南矿区地下水水化学组成及其水文地质意义

Hydrochemistry of Groundwater from the Huainan Coalfield and Their Hydrological Implications

摘要: 为查明淮南矿区不同含水层(松散、煤系砂岩和太原组灰岩含水层)地下水的水文地球化学组成及其影响因素，在系统收集资料的基础上，对其常规离子组成进行了综合分析。结果表明，三个含水层地下水的水化学组成存在差异，表明其水化学组成控制因素(主要离子来源)互不相同。其水化学类型以Na-Cl型和Na-HCO₃型为主，反映矿区整体处于排泄区域或地下水补给不充分。Gibbs图、离子之间的相互关系及因子分析结果表明硅酸盐矿物的风化和含Ca、Mg氯盐矿物的溶解(源1)以及含Na硫酸盐及氯盐矿物的溶解(源2)是水化学组成的主要贡献来源。这一结果在Unmix模型分析中得到了进一步的证实，且Unmix模型分析结果表明源1对煤系砂岩含水层地下水贡献率最高，而源2对松散含水层地下水贡献率最高。

Abstract: For getting the information about the hydrogeochemical compositions and influencing factors of groundwater in different aquifers (loose layer, coal-bearing sandstone and limestone aquifer of Taiyuan formation) in Huainan coalfield, the major ion concentrations of groundwater have been analyzed by a series of methods based on the systematic collection of data. The results show that the hydrochemical compositions of groundwater from the three aquifers are different from each other, indicating that the controlling factors (sources of major ions) of hydrochemical compositions are different from each other. The main hydrochemical types are Na-Cl and Na-HCO₃ types, reflecting that the study area is located in the drainage area or the groundwater supply is insufficient. Gibbs diagram, the relationship between major ions and factor analysis suggest that the weathering of silicate minerals, the dissolution of Ca and Mg containing chloride minerals (source 1) and the dissolution of Na containing sulfate and chloride minerals (source 2) are the main contribution sources of hydrochemistry. The result has been further confirmed by the analysis of UNMIX model, and the results of UNMIX model analysis also show that the groundwater from the coal-bearing sandstone aquifer has the highest contribution from the source 1, whereas the groundwater from the loose layer aquifer has the highest contribution from the source 2.