Evaluation of the Impact of Illegal Mining on Vegetation in the Venezuelan Amazon through Multispectral Imagery
- Paper number
IAC-23,B1,7,1,x77969
- Author
Mr. David Serrano, International Space University (ISU), France
- Coauthor
Mr. René Horacio Michel Valencia, SES, Luxembourg
- Coauthor
Ms. Danijela Ignjatovic Stupar, International Space University (ISU), France
- Year
2023
- Abstract
Illegal mining in the Venezuelan Amazon has proliferated in the last decade, due to multiple socio-economic factors. In 2016 a 111,843 km^2 region named the {\it Arco Minero del Orinoco} (Orinoco Mining Arch) was unlocked by the government to impulse the national revenue from mineral extraction. However, it has since developed into a framework of unregulated extraction activity. These operations employ artisanal mining techniques, which use heavy metals such as mercury and cyanide to facilitate the extraction of gold and other elements. The deforestation footprint of these mines and their expansion can be visibly tracked through satellite imagery, but the impact they have on the health of the surrounding vegetation cannot be assessed in the visible range. This study aims to characterize the invisible extent of environmental damage caused by illegal mine sites, by assessing the vegetation health degradation in their vicinity, using multispectral satellite imagery. The study is focused on the Cerro Yapacana mine site, located in the state of Amazonas, Venezuela, where illegal gold mining has taken place since the 1980’s. Level-2 data from ESA’s Sentinel-2 satellite is used to compute three vegetation indices: Normalized Difference Vegetation Index (NDVI), Red Edge Position (REP) and Normalized Pigment Chlorophyll Index (NPCI). The spatial changes of these indices are examined visually through the application of index masks, as well as graphically through longitudinal and latitudinal slices of the raster data. Changes over time of the indices are examined in the period 2020 – 2023. Preliminary results show an overall decrease in the value of NDVI between 2020 and 2023 when compared over equivalent latitudes, suggesting a drop in the chlorophyll production capability of the vegetation surrounding the mine site. Additionally, the data demonstrates how elevation variations can be used to identify regions of higher vegetation contamination risk, due to drainage gradient. The next phase of the investigation will seek to compare vegetation health between sections in the vicinity of the selected mine site, and a control location not in proximity of a mine.- Abstract document
- Manuscript document
IAC-23,B1,7,1,x77969.pdf (🔒 authorized access only).
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