Subsidence in Qinghai—Tibet Plateau Peatlands Driven by Drainage Disturbance and Climatic Variability

Peatlands are globally important carbon sinks, yet these are increasingly threatened by climate change and human disturbances. Among degradation indicators, surface subsidence is gradual and challenging to monitor, particularly in alpine peatlands. This study applied SBAS-InSAR techniques to analyze surface deformation in the Zoige peatland of the eastern Qinghai—Tibet Plateau using Sentinel-1 SAR data from 2017 to 2023. The results showed a maximum interannual subsidence of −167.92 mm and a peak seasonal deformation of −144.11 mm, with a cumulative average of −23.99 mm (−3.43 mm·yr−1). Approximately 80.9% of peatlands within the protected area exhibited subsidence. Drainage ditch construction emerged as the dominant driver, while climatic factors such as precipitation and temperature exhibited seasonal effects. Subsidence was more pronounced in drier years and during winter months. These findings highlight the spatial heterogeneity and seasonal dynamics of peatland subsidence and underscore the urgent need for hydrological restoration and long-term monitoring to mitigate degradation in alpine peatland ecosystems.