Assessing Regional Land Subsidence Exposure and Geohazard Susceptibility Along the Mexico-Toluca Intercity Railway: An SBAS-InSAR Analysis

Abstract

This study assesses ground subsidence and surface angular distortion along the Lerma–Zinacantepec segment of the Mexico-Toluca Intercity Railway. A multitemporal Interferometric Synthetic Aperture Radar (InSAR) framework using the Short Baseline Subset (SBAS) algorithm processed Sentinel-1 imagery (2022–2024), validated against the MXTO Global Navigation Satellite Systems (GNSS) station (R2 of 0.86 and 0.80 for descending and ascending tracks, respectively). Kinematic vector decomposition revealed a mean vertical ground subsidence rate of −2 cm/year. To evaluate geohazard susceptibility, angular distortion was computed from these decomposed vertical displacements using a fixed 160 m spatial baseline. By explicitly integrating intrinsic InSAR measurement uncertainty into the classification, localized steep gradients initially flagged by mathematical models were discarded as statistically negligible artifacts. Consequently, results show widespread ground stability, with the evaluated 16-km segment falling within low-risk thresholds. Corroborating this, in-situ visual inspections revealed no structural damage induced by differential subsidence. Due to Sentinel-1 pixel-mixing limitations, the measured signals represent ground subsidence rather than direct structural deformation. Future monitoring should integrate higher-resolution SAR sensors or localized structural health instrumentation to isolate the behavior of the railway superstructure from regional subsidence.