Interpretation of spatial and temporal changes and drivers of ecological source regions based on LightGBM-SHAP

Ecological source areas play a pivotal role in nature preservation and soil conservation. These areas are critical in optimizing land-use patterns and fostering the establishment facilitating the establishment of protected ecological source areas. In this study, two types of state layers of ecological source area change were extracted based on land cover data and integrated with an intelligent algorithm to analyze the role of ecological factors contributing to land change. Recommendations are proposed to enhance the optimization of the ecological spatial pattern within the Yellow River Basin. The results indicate key findings: (1) The ecological source areas in the Daxia River Basin experienced Fluctuations between 1990 and 2020 due to the interconversion of grassland and unused land. The change was relatively smooth during 1990–2000, with the ecological source areas increasing slightly by 16.016 km2. From 2000 to 2010, the proportion of unutilized land transferred to grassland was 6.3%, which is significantly higher than the annual transfer average of 1.6%. This is mainly due to the ecological protection measures in the cities of Linxia and Hezuo. Between 2010 and 2020, economic construction resulted in the loss of grassland, and the percentage of grassland turned out was 7.3%, which was significantly higher than the annual average of 1.8%. (2) In the Daxia River Basin, rainfall, sunlight intensity, temperature, and elevation had a greater impact on land change during the period from 1990 to 2020, with contributions of −0.4, 0.09, 0.08, and −0.26, respectively.