Abstract The purpose of this study is to evaluate what sources principally affect the chemical compositions in the catchment of the upper Nakdong River, South Korea where bedrock mostly consists of silicates as a natural factor. From October 7th to 9th, 2015, thirty-three water samples were collected, including samples from tributaries which run alongside mines. We analyzed the major anions, cations, trace elements and water isotopes of the samples and the analyzed data are divided into four groups by principle component analysis (PCA). We determined that most of the water samples are influenced by water-rock interactions when we consider the PCA results and the chemical weathering equation line. However, six samples have excess concentrations of sulfate and plot below the equation line. These samples were mostly from streams beside a zinc-cadmium smelter, which was also consistent with the PCA results. Samples near populated area could also be separated into a group via domestic pollution. Based on the PCA and chemical results, the chemical compositions of the river can be affected by two anthropogenic inputs: mine wastes and domestic contaminants.

中文翻译：

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韩国洛东江上游自然和人为对水化学影响的评估

摘要 本研究的目的是评估哪些来源主要影响韩国洛东江上游流域的化学成分，该流域的基岩主要由硅酸盐作为自然因素组成。2015 年 10 月 7 日至 9 日，共采集水样 33 份，其中包括矿山沿线支流的水样。我们分析了样品的主要阴离子、阳离子、微量元素和水同位素，并通过主成分分析（PCA）将分析数据分为四组。当我们考虑 PCA 结果和化学风化方程线时，我们确定大多数水样受到水-岩相互作用的影响。然而，六个样品的硫酸盐浓度过高，并在方程线下方绘制。这些样品主要来自锌镉冶炼厂旁边的流，这也与 PCA 结果一致。居民区附近的样本也可以通过家庭污染分成一组。根据 PCA 和化学结果，河流的化学成分可能受到两种人为输入的影响：矿山废物和生活污染物。