Paleolimnological reconstructions provide insights into hydrological variability of dynamic floodplain lakes. However, spatial and temporal integration of multiple reconstructions often remains underdeveloped because the efficacy of different paleolimnological measurements varies among lakes due to gradients in energy of floodwaters and sediment composition. Here, we use linear discriminant analysis to identify 10 significant elemental concentrations in sediment obtained from multiple sampling campaigns that distinguish among three end-member allochthonous sources for lakes in the Peace-Athabasca Delta (PAD; Canada): Athabasca River, Peace River, and local catchment runoff. Over 90% of sediment samples were correctly classified into original groups after cross-validation due to the distinctiveness of the three end-members, which permitted development of a robust Bayesian mixing model to discern the relative contributions of sediment from the three sources. We evaluate performance of the mixing model via application to sediment cores from two adjacent lakes in the Athabasca sector of the PAD and demonstrate its effectiveness to discriminate three known hydrological phases during the past 300 years. Notably, model results indicated that ~ 60% of the sediment originated from the Peace River during the largest ice-jam flood event on record (1974), which was unrecognized by other methods. The approach provides a new, universal method that can be applied across the full range of sediment composition to quantify changes in source, frequency, and magnitude of sediment delivery by river floodwaters to lakes and is transferable to other dynamic floodplain landscapes where broad range of sediment composition challenges application of other approaches.

中文翻译：

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贝叶斯混合模型框架，用于量化泛滥平原宽泛水文梯度湖泊沉积物来源的时间变化

古湖泊学重建提供了对动态洪泛区湖泊水文变化的见解。然而，由于洪水能量和沉积物成分的梯度，不同古湖泊测量的功效因湖泊而异，因此多次重建的空间和时间整合通常仍然不发达。在这里，我们使用线性判别分析来确定从多次采样活动中获得的沉积物中 10 种重要元素浓度，这些活动区分了和平-阿萨巴斯卡三角洲（PAD；加拿大）湖泊的三个端元外来源：阿萨巴斯卡河、和平河和当地集水区径流。由于三个端元的独特性，90%以上的沉积物样本经过交叉验证后被正确分类为原始组，这允许开发一个强大的贝叶斯混合模型来辨别来自三个来源的沉积物的相对贡献。我们通过应用于来自 PAD 的阿萨巴斯卡区的两个相邻湖泊的沉积岩芯来评估混合模型的性能，并证明其在过去 300 年中区分三个已知水文阶段的有效性。值得注意的是，模型结果表明，在有记录以来最大的冰塞洪水事件（1974 年）期间，约 60% 的沉积物源自和平河，而其他方法无法识别这一点。该方法提供了一种新的、通用的方法，可以应用于整个沉积物成分范围，以量化来源、频率、