Spatio-Temporal Dynamic and Structural Characteristics of Land Use/Cover Change Based on a Complex Network: A Case Study of the Middle Reaches of Yangtze River Urban Agglomeration

Due to the rapid urbanization and industrialization, urban agglomeration has become the area with the most drastic and concentrated land use change. The research on the evolution law and structural characteristics of urban agglomeration land use system is of great significance for the sustainable development. Taking the middle reaches of the Yangtze River urban agglomeration (MRYRUA) of China as the study area, we analyzed the phasic changes from 1980 to 2018 in land use/cover in the MRYRUA as well as the spatial differences between the three core regions. Furthermore, the transfer matrix of land use/cover change (LUCC) was converted to network, with land use types as nodes and conversion relationships between different land types as network connecting lines. Complex network indexes such as centrality, diffusion, and dominant flow were applied to identify the major changes in land use types, key change paths, and transformation patterns. The results show that: (1) in the past 40 years, the building land area in the MRYRUA has increased significantly, while the area of crop land and forest has, and still is, decreasing at an accelerated rate; (2) in terms of the scale, structure, and spatial distribution of land use transfer, there are distinct differences among the three core regions. The Wuhan metropolitan area has the largest intensity of land use transfer and the most drastic structural adjustment; (3) in all four periods, the land use transition network, crop land, and water bodies are the key land use types. Over time, the influence of building land and forest in the land use transition network has increased; and (4) the first transfer direction of each land use type was stable during different periods, such as the transfer of crop land to water bodies and building land, the transfer of water bodies to crop land, and the mutual transformations among crop land and forest, indicating a stable transfer pattern in the MRYRUA.