Landscape Ecological Risk Assessment of the Chaohu Lake Region Based on Dynamic Evolution of Landscape Patterns

In order to maintain the regional landscape ecological security, satellite remote sensing image data in 2011, 2016 and 2021 were utilized to analyze the landscape ecological risk in the Chaohu Lake Region. The ecological restoration project yielded initial results, as construction land area decreased in the later period. Waters emerged as the dominant land type, while grassland area increased over the 10-year period. Conversely, the area of cultivated land, forestland, and waters decreased, with the most significant decrease observed in cultivated land. The dynamic change in landscape patterns exhibited increasing complexity. Waters dominated the landscape, and the patch density (PD) and landscape shape index (LSI) of cultivated land, forestland, waters, and grassland tended to increase. The controlling role of dominant landscape types decreased, while landscape heterogeneity increased. The Shannon's diversity index (SHDI) and evenness index (SHEI) values increased, indicating diversification and equalization in the compositional structure of landscape types. The landscape division index (DIVISION) initially increased and then decreased, whereas the landscape aggregation degree showed an initial decrease followed by an increase. The contagion index (CONTAG) decreased continuously, indicating a decrease in the aggregation density of different land type patches. The highest-risk area increased, while higherrisk and medium-risk areas initially increased and then decreased. The lower-risk area exhibited less change, and the lowest-risk area showed a decreasing trend followed by an increasing trend. The spatial distribution pattern of the landscape ecological risk index displayed a "low on all sides and high in the middle" pattern. These research findings provide scientific references for optimizing land use structure, achieving sustainable landscape management, and maintaining regional ecological balance.