Monitoring for Surface Geological Deformations in Layla-Alaflaj in Central Saudi Arabia Using Satellite Based Remote Sensing and Differential Interferometry (DInSAR) Techniques

Differential Interferometry Synthetic Aperture Radar (DInSAR) is a valuable remote sensing technique that enables monitoring of large geographical areas at a low cost. One of the main applications for this technique is its ability to detect and monitor terrain deformations and morphological changes through quantitative interpretation of measured surface displacements. This is especially advantageous for deformations that are gradually occurring over the years. Layla-Alaflaj is in central Saudi Arabia and is rich in historical morphological features and is vulnerable to new deformations such as Karsts formations and sinkholes. These deformations impact quality of life and stability of infrastructure and projects. The technical workflow involved the acquisition and preprocessing of Sentinel-1 radar images, followed by the application of DInSAR processing to generate displacement maps. These maps were analyzed using rigorous statistical methods, including time series analysis and spatial correlation techniques, to identify deformation trends and patterns. The findings reveal significant subsidence in the region, near Umm Jabal lake, exhibiting the highest subsidence rates. A linear regression analysis of the deformation data at this location yielded by a regression equation where the slope represents a steady subsidence rate of approximately 8.87 mm/year. This rate corresponds to a higher cumulative subsidence observed during the period from April 2024 to October 2024, highlighting the potential influence of seasonal aquifer discharge during the dry season. The aim of this study is to detect surface displacement and monitor their progress and evolution in order to provide early warning and signs for responsible entities to take needed safety measures and adjustments to avoid damage to life and projects infrastructure properties.