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

Abstract

Artisanal and small-scale mining (ASM) is mainly prevalent in developing countries (Abaidoo et al., 2019;S. Keita, 2001;Owusu et al., 2019). A few years ago, small-scale mining was estimated to account for 15%-20% of global non-fuel mineral production (Hentschel et al., 2002). Although the African continent is home to some of the world's most coveted mineral resources, this favorable geological context has largely failed to lead it toward an equitable and sustainable development trajectory (Hilson, 2002). In some African countries, extreme poverty (A. Keita, 2017;Owusu & Dwomoh, 2012) and crop failures due to climate change are driving rural populations, consisting mainly of farmers, to engage in artisanal mining to meet their daily needs. Artisanal mining is currently the most important rural non-farm activity in Africa (Hilson, 2020). It

Structural Controls of the Expansion of Small‐Scale Artisanal Gold of Bouda Area (Kaya‐Goren Green Belt, Burkina Faso) From Remote Sensing

“…The shortwave infrared band for Landsat 8-OLI (0.665) shows a strong positive weighting. The strong positive weights are marked by a low value of the Saley et al, 2021;Ghislain et al, 2021;Gomez, 2004).…”

“…The strong positive weights are marked by a low value of the extraction areas (black pixels), whereas the strong negative weights show a high value of the extraction areas (white pixels). Several previous studies have demonstrated the contribution of the NIR and SWIR 1 band in lithologic mapping through the absorption and reflectance of rock materials in the NIR‐SWIR 1 domain (Abass Saley et al., 2021; Ghislain et al., 2021; Gomez, 2004).…”

“…The application of Minimum Noise Fraction (MNF) is used for the identification of the extraction areas (Figure 4, left branch) following a previously successful application in the Sahelian region (Abass Saley et al., 2021). Fieldwork data were examined in Google Earth Pro 7.3 software (archive images) and used to refine the contours of extraction areas with greater precision.…”

“…The Minimum Noise Fraction (MNF) and Principal Component Analysis (PCA) followed by direction filters were applied as alternative approaches to identify potential mining sites (Figure 4). The two techniques have been successfully used for the detection of mining sites in other locations (Abass Saley et al., 2021; Aretouyap et al., 2020; Gannouni & Gabtni, 2015; Ghislain et al., 2021; Ibrahim & Mutua, 2014; Ourhzif et al., 2019). Due to insecurity issues, a short period of fieldwork (3 days) was carried out on the Bouda site.…”

“…Remote sensing has been successfully used in exploration geology (Bedini, 2011, 2017; Hu et al., 2018; Ibrahima et al., 2018; Pour & Hashim, 2015a, 2015b) for interpreting spectral signatures over relatively large areas of interest (Girija & Mayappan, 2019; Rajesh, 2004) and identifying new prospects (Amer et al., 2012; Pour & Hashim, 2011). These tools were also successfully employed for mapping and monitoring the expansion and environmental impacts of artisanal mining in Ghana (Forkuor et al., 2020), Senegal (Ngom et al., 2020), Côte d’Ivoire (Ngom, Mbaye, et al., 2022), Niger (Abass Saley et al., 2021). The current study aims to optimize the definition of prospecting corridors in the Bouda area based on the spatiotemporal dynamics of exploitation correlated with structural analysis.…”