Assessing Forestry Reclamation Success in Lignite Mine External Dumps Using Remote Sensing Techniques

Open-pit lignite mining causes significant environmental alterations, particularly through the removal of soil deposits and the creation of external dumps, which necessitate effective reclamation to restore landscape structures. This study evaluates the potential of using multi-temporal remote sensing data to assess the effectiveness of forest reclamation on selected external dumps of the Adamów, Bełchatów, and Turów Lignite Mines in Poland. Using Landsat imagery spanning five decades from 1976 to 2023, the study monitors vegetation development through the Normalized Difference Vegetation Index (NDVI) and the Soil-Adjusted Vegetation Index (SAVI). Reclaimed forest stands were compared against undisturbed reference forests within a 30 km buffer zone, with recovery defined as achieving 95% of the reference values. The results indicate that most studied sites reached a state of recovery, with success closely linked to the specific reclamation measures implemented and the age of the forest stands. Notably, the Adamów mine, which utilized Bender’s target species method, demonstrated rapid results, achieving high similarity to reference forests early in the analyzed period. In contrast, recovery in Bełchatów and Turów was more gradual, following trajectories influenced by pioneer and biodynamic afforestation methods. Ultimately, the study confirms that remote sensing is a highly efficient tool for monitoring extensive post-mining areas over long periods, providing a general assessment of biological restoration success.