Urban growth and its determinants across the Wuhan urban agglomeration, central China

Abstract

China has witnessed rapid urban growth over the past two decades, which has resulted in vast ecological and environmental issues, both in urban and peri-urban areas. It is therefore extremely important to explore the driving factors, and thus gain an insight into the process of urban growth, to be able to provide help for urban planning and policy making. This paper examines the features and spatial determinants of urban growth in the Wuhan urban agglomeration (WUA) from 1988 to 2011. Four landscape metrics (patch density, landscape shape index, aggregation index, and total area) were selected to characterize the urban landscape features at two scales (5 km and 10 km grid sizes). Spatial regression models were then used to explore the relationships between urban landscape change and its spatial determinants. The results showed that the urban area of the WUA increased from 4.19 × 104 ha in 1988 to 49.29 × 104 ha in 2011, with an annual growth rate of 46.75% over the past two decades. The WUA landscape has also become more fragmented and irregular. Spatial autocorrelations were common in the urban growth changes at the two different scales. Both physical and proximity factors have significantly influenced the urban landscape changes, and they have varied with time and scale. Among these variables, all the levels of road network have had a considerable effect on the shape and density changes of the urban landscape, while distance to railway and highway did not show obvious effects on the total area change of the urban growth. In addition, city center has had an increasing effect on patch density, and a decreasing impact on the total area of the urban landscape. The different land-use policies should be compromised and reconciled so that the objectives of promoting socioeconomic development and farmland protection can be balanced. These results could help us to better understand the process of urban growth, and thus have important implications for urban management and policy making in metropolitan areas in developing countries.