oa Satellite-Based Monitoring of Landslides in Mountainous Areas Using Orthorectified ALOS PALSAR-1 DEM and Sentinel-1 Time Series Change Detection

Landslides in mountainous regions pose significant threats to infrastructure, ecosystems, and human safety. Accurate and timely detection of slope instability is crucial for hazard mitigation and spatial planning. This study presents an integrated remote sensing approach for monitoring landslides in mountainous areas using orthorectified ALOS PALSAR-1 radar imagery and time series change detection from Sentinel-1 SAR data.

A Digital Elevation Model (DEM) was generated from orthorectified ALOS PALSAR-1 data to accurately represent terrain morphology and support spatial alignment of multi-source datasets. Sentinel-1 Ground Range Detected (GRD) images were processed to detect changes in backscatter intensity across selected time intervals. This radar-based change detection method allows the identification of surface disturbances indicative of landslide activity, even in areas affected by vegetation or cloud cover.

The combined use of structural topographic data and temporal radar analysis enhances the reliability of landslide detection, particularly in inaccessible or poorly monitored regions. The approach was tested in a mountainous region with known slope instabilities and demonstrated the potential for both rapid post-event assessment and ongoing geohazard monitoring.

This methodology contributes to operational landslide mapping workflows and supports early warning systems, risk assessment, and resilient land management strategies in high-relief environments.