Instituto Federal do Triângulo Mineiro (IFTM), Campus Uberaba, Laboratório de Geoprossessamento, Uberaba, MG, 38064-790, Brazil.
Centro de Investigação e Tecnologias Agroambientais e Biológicas (CITAB), Universidade de Trás-os-Montes e Alto Douro (UTAD), Ap. 1013, 5001-801, Vila Real, Portugal.
Environ Pollut. 2022 Aug 1;306:119341. doi: 10.1016/j.envpol.2022.119341. Epub 2022 Apr 22.
This study investigated the collapse of B1 mine-tailings dam that occurred in 25 January 2019 and severely affected the Brumadinho region (Minas Gerais state, Brazil) socially, economically and environmentally. As regards water resources, the event impacted the Paraopeba River in the first 155.3 km counted from the dam site, meaning nearly half the main water course downstream of B1. In the impacted sector, high concentrations of tailings-related Al, Fe, Mn, P in river sediment-tailings mixtures and water were detected, as well as changes to the reflectance of riparian forests. In the river water, the metal concentrations raised significantly above safe levels. For caution, the water management authorities declared immediate suspension of Paraopeba River as drinking water source to the Metropolitan Region of Belo Horizonte (6 million people), irrespective of representing nearly 30% of all supply. In this study, the main purpose was to assess potential links between tailings distribution, river water composition and reflectance of forest vegetation, which worked out as latent variables in regression models. The latent variables were represented by numerous physical and chemical parameters, measured 4 times in 22 sites during the dry period of 2019. The modeling results suggested the release of aluminum and phosphorus from sand fractions in the mine tailings as major cause of water contamination. The NDVI changes were interpreted as environmental deterioration. Changes in redox potential may have raised manganese concentrations in surface water further affecting the forest NDVI. Distance from the B1 dam and dissolved calcium appear to attenuate deterioration. Overall, the regressions allowed robust prognoses of environmental deterioration in the Paraopeba River under low flow conditions. More importantly, they can be transposed to similar dam ruptures helping environmental authorities to decide upon measures that can bring the affected rivers to pre-rupture conditions.
本研究调查了 2019 年 1 月 25 日发生的 B1 尾矿坝溃坝事件，该事件对巴西米纳斯吉拉斯州布鲁马迪纽地区造成了严重的社会、经济和环境影响。就水资源而言，该事件影响了距离坝址上游 155.3 公里的帕拉奥佩巴河，这意味着 B1 下游近一半的主要河道都受到了影响。在受影响的区域，检测到河流沉积物-尾矿混合物和水中与尾矿有关的 Al、Fe、Mn、P 的浓度很高，以及河岸森林反射率的变化。在河水中，金属浓度显著上升到安全水平以上。出于谨慎考虑，水资源管理当局立即宣布暂停将帕拉奥佩巴河作为贝洛奥里藏特大都市区（600 万人）的饮用水源，尽管该河的供水量几乎占总供水量的 30%。在本研究中，主要目的是评估尾矿分布、河水成分和森林植被反射率之间的潜在联系，这些联系在回归模型中表现为潜在变量。潜在变量由 2019 年旱季在 22 个地点测量的 4 次的许多物理和化学参数表示。建模结果表明，尾矿中砂粒释放的铝和磷是造成水污染的主要原因。NDVI 的变化被解释为环境恶化。氧化还原电位的变化可能会进一步提高地表水的锰浓度，从而进一步影响森林的 NDVI。与 B1 大坝的距离和溶解钙似乎可以减轻恶化。总的来说，回归分析允许对低流量条件下帕拉奥佩巴河的环境恶化进行可靠预测。更重要的是，它们可以转化为类似的大坝破裂，帮助环境当局决定采取措施，使受影响的河流恢复到破裂前的状态。
