Key points are not available for this paper at this time.
Peatland degradation in tropical regions threatens carbon storage and land stability. This study monitored peatland subsidence using the Small Baseline Subset (SBAS) InSAR technique with Sentinel-1 C-band SAR data (2017–2022) in Sub-Peat Hydrological Zone 1. Time-lagged correlation analysis evaluated relationships between vertical displacement and environmental variables (groundwater level, rainfall, and Enhanced Vegetation Index). Vertical displacement rates ranged from −12.6 to 3.6 cm/year, where negative values indicate subsidence while positive values indicate relative surface uplift. The most significant subsidence was concentrated around drainage canals and infrastructure. A Pearson correlation revealed a moderate negative relationship between groundwater levels and subsidence (r = −0.44, p < 0.001), while rainfall and vegetation showed negligible correlations. Cross-correlation analysis revealed that groundwater significantly influences subsidence dynamics, with a persistent negative correlation peaking at r = −0.6 with a 10-month lag. In contrast, rainfall showed delayed indirect effects (r = −0.33 at lag 4), mediated by groundwater recharge, while vegetation showed consistently negligible correlation. These findings confirm groundwater level as the primary hydrological control on subsidence dynamics. Nevertheless, subsidence dynamics were not fully explained by the examined variables, suggesting that additional factors such as peat thickness heterogeneity, fire history, and land-use intensity warrant investigation in future studies.
Setyaningrum et al. (Fri,) studied this question.