Vegetation Resilience Evaluation of Coal Waste Dumps After Reclamation in Arid and Semi-Arid Mining Areas Based on Temporal Satellite Imagery

Open-pit mine waste dumps often exhibit unstable ecological recovery due to the limitations of artificial reconstruction process, despite undergoing land reclamation efforts. Especially in arid and semi-arid mining regions, where harsh climatic conditions and drought events often occur, exacerbating the vulnerability of vegetation to degradation and hinder restoration efforts. Therefore, it is crucial to conduct continuous monitoring to ensure the stability of vegetation restoration and succession of coal waste dumps after reclamation. This study employed Landsat time series imagery combined with BFAST change detection algorithm to evaluate the vegetation resilience of two reclaimed coal waste dumps, the North coal waste dump (NCWD) and the South coal waste dump (SCWD), in a typical arid and semi-arid mining area in China, focusing on both resistance and recovery rate. The results viewed that all pixels across both dumps experienced 2–5 breakpoints from 2013 to 2021. Compared to the NCWD, the SCWD exhibited fewer breakpoints overall. 86.11% and 93.31% of pixels in NCWD and SCWD, respectively, can be effectively recovered after a long-term drought. However, the recovery rate was generally low, primarily concentrated in 0–0.002, highlighting the negative impact of extreme drought events on vegetation restoration. Vegetation resilience exhibited a distinct spatial distribution influenced by terrain characteristics. Generally, steeper slope, higher elevation, and windward direction (N-W) were associated with lower vegetation resistance. Besides, vegetation status before severe drought significantly influenced the vegetation resilience. The NDVI before drought events were positively correlated to the recovery rate of NCWD (r = 0.318, p < 0.01) and SCWD (r = 0.301, p < 0.01), respectively. It was also observed the positive effect of artificial management on vegetation resilience of coal waste dumps, as shown by the superiority of SCWD to NCWD in terms of resistance and recovery rate. Our research provided valuable reference for land reclamation and post-reclamation management measure of coal waste dumps in arid and semi-arid mining areas.