Analysis of Landscape Pattern Changes and Driving Factors of Desertified Land in the Shiyang River Basin

Quantifying the spatial heterogeneity and evolutionary processes of desertified land is essential for improving understanding of ecological dynamics in inland river basins of arid regions and for formulating ecological restoration strategies and sustainable oasis development. This study used nearly 30 years (1992–2022) of remote sensing imagery for the basin as the data source. Desertified-land landscapes were extracted with ENVI and ArcGIS, and landscape pattern metrics were used to analyze changes and trends. The geographic detector model was further applied to explore driving factors influencing the landscape pattern of desertified land. The results show that: (1) Over the past three decades, the area of desertified-land landscapes fluctuated but decreased overall by 4,631.86 km2. Fixed sandy land exhibited the largest change magnitude, with a dynamic rate of −2.31%. Desertified-land types were mainly distributed in non-channel areas of the mid- to lower-reach of the basin; the centroids of fixed and semi-fixed sandy land shifted generally southwestward, whereas mobile dunes and deflation residual dunes expanded northeastward. (2) The landscape pattern of desertified land shifted from dispersed toward more aggregated, with an overall reduction in landscape fragmentation and a tendency toward a relatively stable ecological configuration. (3) Changes in desertified-land landscape pattern were primarily driven by natural factors, with climate (temperature and precipitation) consistently identified as the core drivers. Interaction effects among factors were generally stronger than single-factor effects, indicating a driving regime dominated by natural forces with human activities serving a coordinating role.