贵阳市地表水地下水化学组成:喀斯特水文系统水-岩反应及污染特征

Chemical compositions of surface and ground waters of Guiyang city: discussion of water-rock interaction and contamination in karstic hydrological system

为了解喀斯特地区水-岩相互作用特征和辨别地下水污染物的来源,为揭示人类活动对喀斯特地下水文地球化学环境的影响,研究了贵州省贵阳市不同岩性含水层地下水和地表水的化学特征。结果发现,地表和地下水主要有HCO3型和SO4型以及这两种化学类型的混合型。地下水地表水化学溶解物质主要来源于碳酸盐岩和碎屑沉积岩的化学风化作用,硫酸盐矿物的溶解和硫化物氧化形成的硫酸对岩石矿物的化学风化是导致水体富集硫酸盐的主要因素。区内地表水和地下水的主要污染物质为K+、Na+、Cl-、SO42-和NO3-。这一研究成果为评价地表/地下水环境的质量现状,为喀斯特地区地表水地下水资源的保护和利用提供了科学依据。

In order to know the characteristics of water-rock interaction and the sources of the contaminants in the ground water system of the karstic area, we carry out a study on the water geochemistry of the surface and ground water in Guiyang, the capital city of Guizhou Province, China. The waters are characterized mainly by the HCO3 and SO4 type, as well as their mixed type. The solutes of the studied waters are .mainly derived from the weathering of the carbonate and clastic sedimentary rocks, among which the sulfate ions are probably from the dissolved gypsum and the oxidation of the sulfide minerals in coal-contain- ing strata. Most of K^＋、Na^＋、Cl^-、SO4^2- and NO3^- are anthropogenic in origin. The results of this work are applicable to the assessment of water quality and human impacts on the ground water system, and can be used as the data-base for the protection and exploitation of water resources from the surface/ground water system in the karstic area.