Evolution of the Koma Bangou Gold Panning Site (Niger) From 1984 to 2020 Using Landsat Imagery

The severe drought of 1983–1984 in the Sahel region, and its socio-economic impacts for people relying on farming had consequence first major gold rush at Koma Bangou southwestern part Niger. Initiated 1984, panning activities were interrupted from 1989 to 1999 with exploration permits assigned mining industry. site was reclassified year-end as a artisanal resumed until present-day. Gold such ore extraction cyanide processing produced waste including rocks, mine tailings, treatment residues. Mining is serious environmental, health safety problem. Multispectral Landsat images (TM4-5, ETM7+, OLI/TIRS) acquired between 1984 2020 used map spatial evolution generated by Bangou. Different methods tested, Minimum Noise Fraction (MNF) transform, Band Ratio (BR), Feature Oriented Principal Component Selection (FPCS). FPCS applied hydroxyl-bearing minerals appears be most efficient cyanidation areas. surface associated has increased 9.43 ha 234.20 2020, continuous expansion during period clandestine activity (1989–1999). 5.56 2009 (the year introduction) 99.53 2020. multispectral imagery proved suitable data source monitoring consequences public policies