Abstract：
Understanding the origins of sediment transport in river systems is crucial for effective watershed management, especially after catastrophic events. This information is essential for the development of integrated strategies that guarantee water security in river basins. The present study aimed to investigate the rupture of the B1 tailings dam of the Córrego do Feijão mine, which drastically affected the Brumadinho region (Minas Gerais, Brazil). To address this issue, a confluence-based sediment fingerprinting approach was developed through the SedSAT model. Uncertainty was assessed through Monte Carlo simulations and Mean Absolute Error (MAE). Estimates of the overall average contributions of each tributary were quantified for each station and annually during the period 2019-2021. It was observed that the sampling point PT-09, closest to the dam breach, contributed to almost 80% of the Paraopeba River in 2019. Despite the dredging efforts, this percentage increased to 90% in 2020 due to the need to restore the highly degraded area. Additionally, the main tributaries contributing to sediment increase in the river are Manso River \"TT-03\" (almost 36%), associated with an area with a high percentage of urban land use, and Cedro stream \"TT-07\" (almost 71%), whose geology promotes erosion, leading to higher sediment concentration. Uncertainties arise from the limited number of available tracers, variations caused by dredging activities, and reduced data in 2020 due to the pandemic. Parameters such as land use, riparian vegetation degradation, downstream basin geology, and increased precipitation are key factors for successfully assessing tributary contributions to the Paraopeba River. The obtained results are promising for a preliminary analysis, allowing the quantification of key areas due to higher erosion and studying how this disaster affected the watershed. This information is crucial for improving decision-making, environmental governance, and the development of mitigating measures to ensure water security. This study is pioneering in evaluating this methodology in watersheds affected by environmental disasters, where restoration efforts are ongoing.
摘要：
了解河流系统中泥沙运输的起源对于有效的流域管理至关重要，尤其是在灾难性事件之后。这些信息对于制定确保流域水安全的综合战略至关重要。本研究旨在调查CórregodoFeijão矿的B1尾矿坝的破裂，这严重影响了布鲁马迪尼奥地区(米纳斯吉拉斯州，巴西)。为了解决这个问题，通过SedSAT模型开发了一种基于汇合的沉积物指纹方法。不确定性通过蒙特卡罗模拟和平均绝对误差(MAE)进行评估。在2019年至2021年期间，每个支流的总体平均贡献的估计都是针对每个站点和每年进行量化的。据观察，最靠近大坝溃口的采样点PT-09，2019年贡献了近80%的Paraopeba河。尽管进行了疏浚工作,由于需要恢复高度退化的地区，这一百分比在2020年增加到90%。此外,导致河流泥沙增加的主要支流是曼索河“TT-03”(近36%)，与城市土地利用比例高的地区相关，和Cedro流“TT-07”（几乎71％），其地质促进了侵蚀，导致较高的沉积物浓度。不确定性来自有限数量的可用示踪剂，由疏浚活动引起的变化，由于大流行，2020年的数据有所减少。土地利用等参数，河岸植被退化，下游盆地地质，降水增加是成功评估支流对Paraopeba河的贡献的关键因素。获得的结果是有希望的初步分析，允许量化由于更高的侵蚀而导致的关键区域，并研究这场灾难如何影响分水岭。这些信息对于改善决策至关重要，环境治理,以及制定缓解措施以确保水安全。这项研究是在受环境灾害影响的流域中评估这种方法的先驱，修复工作正在进行中。
