Detection and Monitoring of Small-Scale Mining Operations in the Eastern Democratic Republic of the Congo (DRC) Using Multi-Temporal, Multi-Sensor Remote Sensing Data
Report of the project:
- DR Congo - Strengthening of control in the mining sector of the DR Congo
- DR Congo – Strengthening of control in the mining sector of the DR Congo
- DR Kongo - Stärkung der Kontrolle im Rohstoffsektor
- DR Kongo - Stärkung der Kontrolle im Rohstoffsektor
Subset of the study area in South Kivu, Democratic Republic of the Congo. Description (f. l. t. r.): Sentinel-2 – NDVI, Sentinel-2 – Composite: Red-Green-Blue (4-3-2), SPOT 7 – Composite: NIR-Red-Green (4-3-2), Landsat-8 – Composite: SWIR-NIR-Red (6-5-4), Sentinel-1 – VV-Polarization.
Source: BGR
Mining of so-called “conflict minerals” is often related with small-scale mining activities. Those activities are located in forested areas in the eastern DRC, which are often remote, difficult to access and insecure for geological field inspection. In order to accelerate their CTC (Certified Trading Chain)-certification process, remote sensing data are used for detection and monitoring of these small-scale mining operations. This requires a high image acquisition frequency due to mining site relocations and for compensation of year-round high cloud coverage, especially for optical data evaluation. Free and open source medium resolution optical data of Sentinel-2 and Landsat-8 as well as SAR data of Sentinel-1 are used for detecting small mining targets with a minimum size of approximately 0.5 km². The developed method enables a robust multi-temporal detection of mining sites, monitoring of mining site spatio-temporal relocations and environmental changes. Since qualitative and quantitative comparable results are generated, the followed change detection approach is objective and transparent and may push the certification process forward. A particular emphasis is placed on the use of sensors from the European Earth observation program Copernicus.
The Normalized Differenced Vegetation Index (NDVI), calculated from Sentinel-2 data, is shown in the figure on the left. Green colors correlate with healthy, vital vegetation.