An Earth Observation based story of El Bagre Zaragoza small scale mining - Agosto 2020

Informal small-scale mining occurs is many countries and provides livelihood to many families in rural areas. Yet, it often creates devastating social and environmental impacts. A study case in Colombia greatly affected by small-scale alluvial gold mining, also known as placer mining, is considered. The objective is to utilize the free data of Sentinel-2 to identify mining areas and to understand the dynamics in landcover change over the study area located at the border of the municipalities of El Bagre and Zaragoza in Bajo Cauca, Colombia. To overcome the constraints of pixel-based and object-based approaches, the study utilizes a pixel-based approach followed by post-processing using field knowledge. The results achieve an in-depth understanding of spatial and temporal variations of the landcover in the area, with the focus on areas impacted by mining activities. Image processing techniques used for this purpose are supervised classification and sequential pattern mining of classified images.