Exploring the Ecological Security Network in the Gansu Section of the Yellow River Basin in China

Rapid urbanization has led to severe landscape fragmentation and ecosystem degradation in the Gansu Section of the Yellow River Basin (GSYRB). Focusing on this region, this study identified the spatial distribution of key ecological elements; consequently, an integrated “source–corridor–pinch point” ecological network was constructed. The findings aim to optimize the regional ecological security pattern. Ultimately, this study provides a scientific basis for the sustainable development of the study area and similar regions. This study revealed ecological trends based on four periods of land use data (1993–2023). We identified ecological source areas through MSPA and ecosystem service evaluations, and constructed resistance surfaces using spatial PCA. By applying circuit theory, we extracted ecological corridors—incorporating width attributes—and identified pinch points, thereby establishing a comprehensive ecological network. The results show that: (1) Over the past 30 years, construction land area expanded significantly, while cultivated land and water body areas contracted, and grassland and forest areas increased slowly. (2) Both the landscape fragmentation index and connectivity index exhibited a downward trend, while the landscape diversity index decreased first and then increased, indicating a systemic transformation in the landscape pattern. (3) A total of 260 ecological source areas, 694 ecological corridors (linear pathways connecting ecological source areas), and 371 ecological pinch points (critical bottleneck sections within corridors where connectivity is most vulnerable to disruption) were identified, forming an overall network structure with uneven spatial distribution. The ecological network spatial pattern constructed in this study based on ecosystem service assessment and circuit theory can effectively identify key ecological elements and their spatial heterogeneity characteristics, providing scientific reference for optimizing regional ecological security patterns and biodiversity conservation.