Abstract：
The present study aimed to investigate the rupture of B1 tailings dam of Córrego do Feijão mine, which drastically affected the region of Brumadinho (Minas Gerais, Brazil). The contamination of water resources reached 155.3 km from the dam site. In the river channel, high concentrations of Mn, Al, As and Fe were detected and correlated to the spillage of the tailings in the river. The presence of the tailings also affected the chlorophyll-a content in the water, as well as the reflectance of riparian forests. With the increase of metal(oid) concentrations above permitted levels, water management authorities suspended the use of Paraopeba River as resource in the impacted areas, namely the drinking water supply to the Metropolitan region of Belo Horizonte. This study aimed to evaluate possible links between tailings distribution, river water quality, and environmental degradation, which worked as latent variables in partial least squares regression models. The latent variables were represented by numerous physical and chemical parameters of water and sediment, measured four times in 22 locations during the rainy season of 2019, in addition to stream flow and to NDVI evaluated in satellite images processed daily. The modeling results suggested a relationship between river flow turbulence and increased arsenic release from sand fractions, as well as desorption of Mn from metal oxides, both representing causes of water quality reduction. They also revealed increasing iron concentrations affecting the forest NDVI (greening), which was interpreted as environmental degradation. The increase of chlorophyll-a concentrations (related with turbidity decreases), as well as the increase of river flows (responsible for dilution effects), seemed to work out as attenuators of degradation. Although applied to a specific site, our modeling approach can be transposed to equivalent dam failures and climate contexts, helping water resource management authorities to decide upon appropriate recovery solutions.
摘要：
本研究旨在调查CórregodoFeijão矿B1尾矿坝的破裂，这严重影响了布鲁马迪尼奥(米纳斯吉拉斯州，巴西)。距坝址155.3公里的水资源污染。在河道里,高浓度的锰，Al,As和Fe被检测到，并与河流中尾矿的溢出有关。尾矿的存在也影响了水体中叶绿素a的含量,以及河岸森林的反射率。随着金属(oid)浓度增加到允许水平以上，水管理当局暂停使用Paraopeba河作为受影响地区的资源，即贝洛奥里藏特都会区的饮用水供应。本研究旨在评估尾矿分布之间的可能联系，河流水质,和环境退化，它在偏最小二乘回归模型中用作潜在变量。潜在变量由水和沉积物的许多物理和化学参数表示，在2019年雨季期间，在22个地点进行了四次测量，此外，在每天处理的卫星图像中评估了溪流和NDVI。建模结果表明，河流湍流与砂粒中砷释放增加之间存在关系，以及从金属氧化物中解吸Mn，两者都代表了水质下降的原因。他们还揭示了铁浓度的增加会影响森林NDVI（绿化），这被解释为环境退化。叶绿素a浓度增加（与浊度降低有关），以及河流流量的增加(导致稀释效应)，似乎是退化的衰减器。虽然适用于特定网站，我们的建模方法可以转换为等效的大坝破坏和气候环境，帮助水资源管理当局决定适当的恢复解决方案。
