Spatial correlation characteristics of urbanization and land ecosystem service value in Wuhan Urban Agglomeration

Abstract: As one of the largest developing countries in the world, China has entered an accelerating period of urbanization with significant growth of economy and population. However, the ecological and environmental issues have directly threatened the sustainability of social and economic development in the country. In order to promote ecosystem quality in the high-speed urbanization process as well as provide scientific and feasible basis for differentiated and sustainable land use, this paper tried to explore the spatial correlation between urbanization and ecosystem service value (ESV). In the research, a metropolitan region in Central China called Wuhan Urban Agglomeration was selected as the study area. Located in the middle reaches of the Yangtze River, it is one of the most important regions with abundant agricultural and industrial products. According to the 4 aspects of urbanization concept involved population growth, economic development, urban space expanding and life quality improvement, 4 indicators, including proportion of urban permanent residents, proportion of built-up land, output proportion of non-agro industries and per capita disposable income of urban resident, were adopted to measure the levels of population urbanization, spatial urbanization, economic urbanization and living urbanization respectively. These data were collected from Hubei Statistical Yearbook in 2011. The land use data were derived from land use survey in 2010 and the outputs of crops in the study area were also calculated based on statistical data. The ESV of each land use type in Wuhan Urban Agglomeration was evaluated based on Costanza's evaluation formula and "equivalent value of ecosystem services per unit area in China". Both the spatial characteristics of urbanization and the ESV of all the 39 units were analyzed at the county level. Then the correlation between urbanization and ESV was calculated by utilizing bivariate spatial autocorrelation method. The results showed that the levels of urbanization and ESV in the study area both varied obviously in different areas. Urbanization was characterized by a structure with double centers and decreasing outward from centers, where the western area was basically higher than the eastern area. As to the ESV per hectare, the counties in the south hilly region were clustered to be the highest group. However, the lowest group was the counties clustered in the west and northwest region in Jianghan Plain, not the big cities such as Wuhan or Huangshi, probably because this area was located in a main crop production region with much lower forest coverage. According to the bivariate spatial autocorrelation analysis, population urbanization was discovered to have the strongest negative correlation with ESV, followed by spatial urbanization and then living urbanization. Specifically, spatial urbanization and living urbanization had the most significant negative correlations with raw materials value, and the negative impacts of population urbanization, spatial urbanization and living urbanization on gas regulation value and soil conservation value were also very obvious. What's more, the bivariate LISA figures between different urbanization indicators with ESV had similar spatial characters. The high-low clusters were located in the central part of Wuhan Urban Agglomeration, whose economy was more developed. The low-high groups mainly gathered in the southern mountainous areas and in the northern Dabie Mountain areas. The research can provide important decision-making basis for regional new-type urbanization and ecological protection in future.