Satellite time-series mapping and driving mechanisms of cropland abandonment in mountainous regions of China.

Cropland abandonment (CA) has become increasingly prevalent in mountainous regions, posing significant challenges to agricultural sustainability, land management, and regional food security. Complex terrain and fragmented land-use patterns hinder long-term and fine-scale assessments of abandonment dynamics, limiting the effectiveness of land management and rural development strategies. This study developed a satellite time-series-based analytical framework to quantify the spatiotemporal patterns and driving mechanisms of CA in a representative mountainous region of Southwest China from 2001 to 2020. Cropland parcels were delineated using object-based image segmentation, and land-use types were classified through a machine-learning approach. Long-term and sustained CA was identified from vegetation trajectory characteristics derived from multi-year satellite observations. The relative contributions of natural and socioeconomic driving factors were further quantified using a spatial statistical model. The results show that: (1) land-use classification achieved consistently high accuracy throughout the study period, with overall accuracies exceeding 80%, and cropland extent declined modestly between 2001 and 2020, accompanied by increases in forest and grassland coverage, while water bodies remained stable and built-up land exhibited limited change; (2) CA affected 4.81%-12.92% of the total cropland area, corresponding to 6262-12,995 ha, and the identification of long-term abandonment achieved an overall accuracy of 81.0%; (3) spatial clustering analysis revealed that abandonment hotspots were primarily concentrated in northern and central mountainous zones and exhibited a gradual weakening trend over time; and (4) precipitation, agricultural population, and gross domestic product were identified as the dominant factors shaping the spatial heterogeneity of CA. Overall, this study provides a transferable framework for long-term monitoring of CA in mountainous environments and offers practical insights for land-use planning, agricultural management, and policy interventions aimed at promoting sustainable development in environmentally sensitive regions.