Assessment of Excavation-Induced Soil and Ecological Degradation in Pumped-Storage Hydropower Construction Areas Using Field Measurements and Time-Series Remote Sensing

Large-scale excavation for pumped-storage hydropower stations (PSPSs) in mountainous areas substantially alters slope soils and accelerates ecological degradation, yet quantitative multi-indicator assessments for such projects remain limited. This study integrates field surveys, laboratory analyses, and multi-temporal remote-sensing data to evaluate the disturbance-induced evolution of soil properties at two representative PSPSs in China. Soil bulk density and porosity measurements revealed significant compaction on disturbed slope surfaces, particularly on soil-dominated slopes. Key nutrient indicators, including organic matter, alkali-hydrolysable nitrogen, available phosphorus, and available potassium, showed consistent declines relative to adjacent undisturbed habitats. A comprehensive ecological degradation indicator (EDI) was constructed using five vegetation and soil spectral indices (RVI, NDVI, SAVI, SBI, and SM) weighted through the analytic hierarchy process. Time-series EDI mapping (2019–2023) demonstrated a progressive increase in moderately to extremely degraded areas during intensive construction stages. The results highlight the strong spatial heterogeneity of disturbance effects and underscore the necessity of soil-focused restoration strategies. This integrated assessment framework provides a scientific basis for guiding near-natural restoration and long-term soil–vegetation management in PSPS infrastructure landscapes.