Remote Sensing Analyses for the Cerro Colorado Mine

Satellite imagery analysis is a cost-effective method for tracking environmental changes over large areas — and long periods — in areas where ground access is impractical. We used this method at the Salar de Lagunillas to establish baseline conditions and to monitor changes in surface water and vegetation over time.


The Cerro Colorado Mine wellfield is located within the Salar de Lagunillas basin — an extremely arid, ecologically sensitive area of Chile that lies at an elevation of about 4,000 meters (13,100 feet) above sea level. The estimated groundwater demand for this mine is about 100 to 150 liters per second.


  • Analyzed more than 50 satellite images, including older Landsat 5 images (198 –2008) and newer QuickBird and WorldView-2 images (2008–2016) for the period February 1986 – July 2016
  • Moved from analysis of low-resolution Landsat 5 images to high resolution QuickBird and WorldView-2 images and adapted analytical methods for newer satellite platforms
  • Selected high-quality, cloud- and noise-free images; georeferenced them to facilitate comparison; and corrected them for differences in sun angle, satellite position, and atmospheric haze
  • Determined the vegetation and surface water areas and assigned vegetation indexes (abundance and health); compared water area results to ground survey data
  • Compared results for basins with and without groundwater pumping
  • Identified potential correlations with precipitation and groundwater pumping
  • Developed a satellite image monitoring system to establish an historic environmental baseline for surface water and vegetation