Mapping Artisanal and Small-Scale Gold Mining in Senegal Using Sentinel 2 Data

Area of Science:

• Earth Observation
• Remote Sensing
• Environmental Monitoring

Background:

• Artisanal and small-scale gold mining (ASGM) is a major income source in Senegal.
• ASGM growth presents environmental, social, and health challenges.
• Government monitoring of ASGM is difficult.

Purpose of the Study:

• To develop a method for detecting and mapping ASGM sites in Senegal.
• To utilize Sentinel 2 satellite data and Google Earth Engine for this purpose.
• To provide a tool for monitoring ASGM evolution.

Main Methods:

• Utilized Sentinel 2 data and Google Earth Engine.
• Applied Principal Component Analysis (PCA) for optimal mapping periods.
• Employed Separability and Threshold (SEaTH) for band/index selection.
• Used Support Vector Machine (SVM) for classification.
• Validated results with field observations.

Main Results:

• The end of the dry season is optimal for mapping ASGM due to minimal vegetation.
• The developed method successfully detected and mapped ASGM sites.
• Classification maps distinguished ASGM from other land uses.

Conclusions:

• The proposed method effectively maps ASGM sites in Senegal.
• This approach can be used for ongoing monitoring of mining activities.
• The methodology is potentially applicable to other regions in the Sahel.