The Study Of Green Infrastructure Spatial Patterns In The Yangtze River Delta Based On MSPA

In the past 30 years,China has experienced a rapid urbanization.It is predicted that by 2030,China will add 310 million urban residents,and the level of urbanization will reach to 70%.This paper takes the urban agglomeration of Yangtze River Delta,which is the most urbanized area in China,and best represents China's economic and social development model,as an example.It studies the spatial and temporal pattern of urban green infrastructure.Firstly,we applied the ArcGIS platform to establish a matrix of land use change between 2000 and 2015.The results showed that:(1)cropland undergone the highest lost,and about 10.6%of the cropland was converted to construction land.The rough and disorderly urbanization in the first decade of the twentieth century led to a large loss of cropland.(2)The reserve rate of forest land is the highest,reaching to 95.80%.The protection of forest resources in the last decade is quite effective.However,about2.24%of the lost forest land was converted to cropland,resulting in the degradation of the ecological value of the land.Based on that,we took green infrastructure(forest land,grassland,waters)as the foreground,and gray infrastructure(cropland,construction land,and unused land)as the background to generate a spatial and temporal distribution map of green infrastructure.In general,the proportion of green infrastructure in urban space has not changed much.Therefore,we further analyze the morphological spatial structure of green infrastructure.The morphological spatial analysis module in GuidosToolBox was used to analyze the spatial structure of the green infrastructure,and the morphological spatial analysis maps for three years were generated.It shows that:(1)The core area that can be used as an ecological source lost 1089.65km~2,of which 63.93%was converted to the edge area.The outward expansion of gray infrastructure is the main cause of continuous erosion.(2)The proportion of branch lines increased sharply with the increase rate of 24.96%,the ecological connection between different habitat patches was cut off,and the connectivity of the landscape declined sharply.Finally,we use the change matrix to analyze the mutual conversion laws of various functional elements during the last fifteen years,in order to provide the best way to protect the ecological source and establish the ecological corridor most efficiently.This paper's research on the characteristics of the spatial and temporal pattern of green infrastructure in the Yangtze River Delta urban agglomeration can provide a reference and basis for green infrastructure construction in rapidly urbanizing areas.In the case of limited ecological protection space and funds,the ecological functions of different green infrastructure elements are maximized,and the problem of landscape fragmentation is solved with minimal investment.Coordinate the contradiction between economic development and environmental protection in the process of rapid urbanization,find the balance between social development and ecological system stability,and achieve sustainable development.