Impact of Climate and Landscape on the Spatial Patterns of Soil Moisture Variation on the Tibetan Plateau

Soil moisture is a critical variable linking the land surface and atmosphere over the Tibetan Plateau. Identifying its spatial variability is essential for understanding the regional water cycle, particularly how landscape features shape soil moisture patterns. While previous studies emphasized climate, topography, and vegetation, the role of land-cover morphology has been largely overlooked. Here, we combined TerraClimate reanalysis and satellite data from 2018 to 2022 with morphological analysis and the GeoDetector method to examine 14 factors affecting soil moisture heterogeneity. Results show that precipitation and vegetation dominate soil moisture distribution, yet the influence of landscape morphology in forests and barren lands exceeds that of temperature. Forest cores retain extremely high soil moisture, while transitional zones such as edges, perforations, and islets play a critical role in grasslands and croplands. Interaction analysis indicates that forests and barren morphologies mainly respond to linear climatic drivers, whereas croplands, grasslands, urban areas, and water morphologies are shaped by nonlinear multi-factor effects. Perturbation experiments further reveal that warming weakens the buffering capacity of forests and enhances drying in grasslands and barren areas. These findings highlight the importance of landscape morphology for predicting soil moisture resilience and improving ecological management on the Tibetan Plateau.