Assessing Slope Stability and Landslide Hazards using InSAR-Based Deformation Monitoring In the India and Vietnam.

Mountainous regions in India and Vietnam are highly vulnerable to landslides due to their complex terrain, active tectonic settings, and intense seasonal rainfall, posing severe risks to infrastructure, ecosystems, and human settlements. This study employs the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique to monitor long-term ground deformation and evaluate slope stability in landslide-prone areas across these regions. Using Sentinel-1 satellite imagery from 2020–2025, SBAS-InSAR was applied to mitigate decorrelation challenges caused by dense vegetation and steep topography, enabling millimeter-scale accuracy in displacement measurements. Time-series deformation maps reveal spatially heterogeneous movement patterns, with accelerated displacement during monsoon periods, strongly correlated with rainfall intensity and geological factors such as fractured bedrock and colluvial deposits. Validation through field observations and geotechnical data confirms the reliability of SBAS-InSAR results, identifying critical failure zones influenced by groundwater infiltration and slope oversteepening. The findings demonstrate the effectiveness of SBAS-InSAR for monitoring slow-moving landslides in remote mountainous regions, providing actionable insights for hazard assessment, early warning systems, and sustainable infrastructure planning. This research underscores the role of spaceborne radar technology in enhancing disaster resilience and risk mitigation strategies in both the Indian Himalayas and northern Vietnam.

 

Keywords: SBAS-InSAR, slope instability,Indian Himalayans, North Vietnam, Sentinel-1, deformation monitoring.