Integrative Approaches to Monitoring Cultivated Land Subsidence in Hilly Regions: Applications of Differential Interferometric Synthetic Aperture Radar and Small Baseline Subset Interferometric Synthetic Aperture Radar Technologies

In response to the challenges faced in monitoring cultivated land in hilly regions, we take a city as a case study to explore the application of differential interferometric synthetic aperture radar (D-InSAR) and small baseline subset InSAR (SBAS-InSAR) technologies in constructing a spatial database for cultivated land monitoring. The complexity and diversity of cultivated land in hilly regions pose challenges for traditional monitoring methods. These methods often fail to meet the required standards for efficiency and accuracy. Therefore, in this study, we selected 20 Sentinel-1A satellite images captured between October 26, 2022 and May 24, 2024, and employed D-InSAR and SBAS-InSAR technologies for the high-precision monitoring of changes in cultivated land and planting attributes. We processed and analyzed the collected data and then compared the performance of the two InSAR technologies in monitoring cultivated land. We found that the maximum cumulative subsidence values detected in the research area by D-InSAR and SBAS-InSAR were 28 and 8 mm, respectively. D-InSAR technology responds quickly to minor changes in cultivated land. However, it is highly sensitive to noise, especially in hilly regions with large topographic variations. SBAS-InSAR technology effectively reduces atmospheric effects and other sources of error. This approach provides more stable and smoother monitoring results for cultivated land. This technical framework is expected to be extended to more hilly regions in the future. It will contribute to the comprehensive protection and rational use of cultivated land nationwide.