The mechanical behavior of gravelly soils in shallow overburden environments is significantly modulated by groundwater fluctuations, which govern the in situ moisture distribution and, consequently, control particle fragmentation processes and the evolution of shear strength. Fragmentation was quantitatively characterized through particle size distribution, fractal dimension, mean particle size, and statistical parameters derived from Weibull and generalized extreme value distributions. Shear strength was evaluated via consolidated–drained triaxial tests. The results demonstrate a clear depth dependency of the soil’s physical and mechanical properties. As the sampling depth increased from 3.0 m to 26.5 m, the natural moisture content decreased from 2.89% to 0.77%. Fractal analysis reveals that the fractal dimension of the particles increased from 2.304 to 2.671, reflecting an intensified fragmentation process at greater depths. Triaxial test results indicate that with increasing depth, the internal friction angle increased from 28.63° to 40°, while the cohesion decreased from 18.59 kPa to 5.47 kPa. These quantitative variations suggest that the coupled effects of groundwater variation and overburden pressure collectively govern the evolution of fragmentation characteristics and the divergent trends observed in shear strength components.

This study focuses on step deformation landslides, conducting spatiotemporal analysis of landslide deformation and instability trends. First, the target landslide area is selected, and geological and precipitation data, along with historical displacement data from monitoring points, are collected. The slope single-change-point analysis method is then employed, combined with landslide profile data, to extract key features from the monitoring data. Next, Small BAseline Subset-Interferometric Synthetic Aperture Radar (SBAS-InSAR) technology is applied to obtain satellite images of the study area. These images, together with the extracted data features, are used to draw the spatiotemporal baseline of the target landslide, completing the spatiotemporal analysis. Finally, a landslide prediction model is developed, and its prediction error is corrected using an Extreme Learning Machine (ELM) neural network. The refined prediction results serve as the basis for analyzing the landslide deformation coefficient, enabling the determination of the landslide instability trend. The experimental results show that step deformation landslides exhibit significant spatiotemporal variability and a short stability period throughout the year. The analytical methods designed in this study outperform traditional methods, providing more reliable results for predicting landslide instability trends.

Accurate semantic segmentation of complex landforms in remote sensing imagery is hindered by pronounced intra-class heterogeneity, blurred boundaries, and irregular geomorphic structures. To overcome these challenges, this study presents LENet (Landforms Expert Segmentation Net), a novel segmentation network that combines axial semantic modeling with deformation-aware compensation. LENet follows an encoder–decoder framework, where the decoder integrates three key modules: the Expert Enhancement Block (EEBlock) for capturing long-range dependencies along axial directions; the Feature Expert Compensator (FEC) employing deformable convolutions with channel–spatial decoupled weights to emphasize ambiguous intra-class regions; and the Cross-Sparse Attention (CSA) mechanism that suppresses background noise via multi-rate sparsity masks and enhances intra-class consistency through cosine-similarity weighting. Experiments conducted on the PKLD plateau karst and GVLM landslide datasets demonstrate that LENet achieves IoU scores of 70.39% and 80.95% and Recall values of 83.33% and 91.38%, surpassing eight state-of-the-art methods. These results confirm that LENet effectively balances global contextual understanding and local detail refinement, providing a robust and accurate solution for complex landform segmentation in remote sensing imagery.