Desertification in northern China from 2000 to 2020: The spatial–temporal processes and driving mechanisms

Desertification is one of the most significant environmental and social challenges globally. Monitoring desertification dynamics and quantitatively identifying the contributions of its driving factors are crucial for land restoration and sustainable development. This study develops a standardized methodological framework that combines desertification dynamics with driving mechanisms at the pixel level, applied to northern China from 2000 to 2020. Using multisource data and employing the Time Series Segmentation and Residual Trend analysis (TSS-RESTREND) method alongside geographical detector, we quantitatively assessed desertification reversion, expansion, and abrupt change processes, along with the impacts and interactions of natural and human factors were quantitatively assessed. Over the past two decades, the proportion of desertified land decreased by 5.60%. Notably, 32.88% of the study area experienced significant desertification reversion, while only 5.86% underwent expansion. Abrupt changes in both reversed and expanding areas were observed, primarily in the central and western regions, with these changes concentrated in the periods of 2009–2011 and 2014–2016. The impacts of various factors in different sub-regions exhibited significant spatial heterogeneity. Increased precipitation, temperature, and evapotranspiration contributed to reversion in the western area, while decreased wind speed influenced the eastern area. Additionally, decreased population density and afforestation activities also promoted desertification reversion. In contrast, decreased precipitation and increased temperature contributed to expansion in the western and eastern areas, respectively, with increased population density exacerbating this process. Overall, the interactions between natural and human factors were enhanced. Future desertification control and ecological engineering planning should focus on the coupling effects of different driving factors and relevant abrupt vegetation changes.