Mapping open-pit mining area in complex mining and mixed land cover zone using Landsat imagery

Abstract

The monitoring of open-pit mining and reclamation activities is an important part of ecological protection across various countries. Among the many methods of monitoring open-pit mining areas, satellite remote sensing is the most widely used and effective. However, few works have been conducted to map open-pit mines over a larger geographical scale, or have considered complex land cover types, or a wide variety of mine properties. This work proposes a framework for mapping open-pit mines for areas over complex land cover and mining properties, including preprocessing, classification, and postprocessing steps. First, the pixels that did not contain mines were masked, second the mines were divided into two categories according to their spectral characteristics, then the selected samples and classified to obtain the classification results of mines, and third mis-classified pixels were removed. This work used Landsat images and Google Earth Engine to map the open-pit mines over Shanxi in 5-year steps from 2000 to 2020. The average producer and user accuracy of the results was found to be 79.4% and 83.2% respectively. The experimental results showed that open-pit mining areas in Shanxi first increased and subsequently decreased over the past twenty years. Additionally, the new preprocessing, classification, and postprocessing workflow was found to be effective, especially in environments with more vegetative cover.