The anthropocene landscape and ecosystem services in the closure of sand mining: Paraíba do Sul River basin – Brazil

Abstract

Geodiversity is a determinant of mining patterns, because its nature defines the interaction with humans, type of exploitation, and, consequently, ecosystem services (ES) of the final landscape. The environmental recovery obligations defined in the legislation serve as a good guidance, but sand mining companies are not always able to finalize their activity entirely and to comply with the laws. To take this into account, the present study was developed with an objective of analyzing the changes observed in the ES after 70 years of sand exploitation in the Paraíba do Sul River Valley, Brazil. The services of the floodplain soil formation and associated components, such as the quality and quantity of water and refuges provided by the riparian forest, are highlighted in this study. To evaluate the different ESs modified by mining, socio-environmental variables were studied, and the analytic hierarchy process (AHP) method was applied to assign significance to each variable in the phase of closing activities, thus creating a compound index for ES evaluation at mine closure. The closure conditions were analyzed against the UN Sustainable Development Goals (SDGs) 6, 8, 9, and 11. The results showed that the companies are small, that they met the legislation in equal criteria of environmental rehabilitation, and that they were induced to a closure standard, reflecting the reforestation with native forest variable, related to the ES of provisioning of habitat to wild fauna. However, the mine facilities variable, associated with the cultural ES of recreation, predominated, because the buildings and access roads were preserved, even though the movable assets were demobilized quickly. It was concluded from the analysis that the scenario of the ES at mine closure is generally linked to geodiversity, company size, and compliance with legal duties.