We tested an integrated multi-isotopic analysis framework to quantitatively estimate anthropogenic organic matter (OM) loads in different land-use types of a watershed (Lake Shihwa, South Korea). The isotopic signatures of increased bulk-element abundances in urban areas and industrial complexes may reflect the mixed contributions of natural and anthropogenic sources. Together with the predominant abundance of n-alkanes and polycyclic aromatic hydrocarbons at both boundaries, specific indices derived from their abundance may be indicative of mixed contributions from terrestrial plants, petroleum, and combustion deposited through various pathways (e.g., atmospheric deposition, outfall pipes, and surface runoff). Based on these properties, compound isotopic signatures (δ13CC27+C29+C31, δ13CFl, δ13CPyr, δ13CBaA+Chry, δ13CIcdP, δ13CBghiP,) for both land-use types may provide significant evidence of an increase in anthropogenic derived-OM loads (> 90 %) in Lake Shihwa. This approach suggests that total organic carbon–weighted source apportionments can provide useful quantitative estimates of OM loads within complex river systems.

中文翻译：

---

石花湖沉积物中天然和人为有机物来源的分配：一种使用分子比和化合物特异性稳定同位素分析的综合方法


我们测试了一个集成的多同位素分析框架，以定量估计流域（韩国石花湖）不同土地利用类型中的人为有机物 （OM） 负荷。城市地区和工业综合体中体元素丰度增加的同位素特征可能反映了自然和人为来源的混合贡献。连同正烷烃和多环芳烃在两个边界上的主要丰度，从它们的丰度得出的特定指数可能表明陆生植物、石油和燃烧通过各种途径（例如，大气沉积、排放管和地表径流）沉积的混合贡献。基于这些特性，两种土地利用类型的化合物同位素特征 （δ13CC27+C29+C31， δ13CFl， δ13CPyr， δ13CBaA+Chry， δ13CIcdP， δ13CBghiP，） 可能为石花湖人为衍生的 OM 负荷增加 （> 90 %） 提供重要证据。这种方法表明，总有机碳加权源分配可以提供复杂河流系统中 OM 负荷的有用定量估计。