Inversion of critical shear strength parameters of landslides using InSAR and MWOA

Efficiently acquiring critical shear strength parameters (CSSP) is essential for slope stability analysis and landslide mitigation. Conventional approaches—primarily based on field sampling and laboratory testing—are labor-intensive, time-consuming, costly, and spatially constrained. These limitations hinder their representativeness and scalability, particularly in the context of large-scale or remote landslides in inaccessible terrain. To overcome these challenges, this study introduces a novel approach that integrates Interferometric Synthetic Aperture Radar (InSAR) data with a Mutation Whale Optimization Algorithm (MWOA) to invert landslide CSSP. The method leverages InSAR-derived surface displacement to reconstruct slip surfaces and establish stability models, enabling the inversion of cohesion and internal friction angle through MWOA optimization. Applied to the Xishancun landslide, the method yields a cohesion of 7.6162 kPa, an internal friction angle of 28.7613°, and a safety factor of 1.0019, closely aligning with results from Geostudio simulations and borehole investigations. Comparative analyses demonstrate that the proposed algorithm achieves higher inversion accuracy than traditional optimization techniques. Additionally, the agreement between the InSAR-inverted and borehole-inferred slip surfaces is validated by a root mean square error (RMSE) of 16.5613 m, an R² of 0.8910, and a correlation coefficient of 0.9848. This approach provides a reliable, efficient, and scalable solution for estimating CSSP, offering significant potential for landslide hazard assessment and early warning in challenging environments.