Construction and evolution of river basin ecological network based on circuit theory and MSPA: A case study of Dawen River Basin

Ecological networks serve as a vital approach for preserving ecosystem health and ensuring regional ecological security. In this study, the Dawen River Basin is selected as the site, and morphological spatial pattern analysis (MSPA) combined with circuit theory is employed to identify ecological sources, ecological corridors, ecological pinchpoints and ecological barrier points. Subsequently, the ecological networks of the basin are constructed for the period from 2000 to 2020. The spatio-temporal evolution characteristics and trends of these ecological networks are analyzed using network structure index. Additionally, restoration strategies are proposed based on the findings. The results showed that: (1) The ecological sources area within the Dawen River Basin has experienced a continuous decline over the past 20 years, decreasing from 1410.42 km2 in 2000 to 1192.42 km2 in 2020. Spatially, the distribution pattern of ecological sources exhibits a higher concentration in the eastern region and a lower density in the western region. (2) The trend for ecological corridors demonstrates an initial decrease in both length and area, followed by an increase. Cropland and built-up land constitute the primary land types within ecological corridors. (3) The area of ecological pinchpoints has continuously decreased, primarily concentrated in the eastern region of the Dawen River Basin. Contrastingly, the area of ecological barrier points increased significantly, with a widespread distribution. These changes indicate an increasing barrier to species migration and a reduction in the connectivity of the ecological network. (4) The index of ecological network structure has generally decreased. To enhance the stability of the ecological network, it is recommended to construct stepping stones and repair ecological obstacles. This study provides critical references for territorial space reform planning in the Dawen River Basin and contributes to the formulation of more effective measures for ecological environmental protection.