The Impact Of Different Urban Spatial Growth Patterns On The Accessibility And Equity Of Urban Green Spaces

The accessibility and equity of urban green space are crucial for the delivery of services provided by urban green space to urban residents,which have become important indicators for assessing the ecosystem services of urban green space and are of great importance to urban spatial planning.Taking the city of Guangzhou,which has significant changes in urban green spaces during the rapid process of urbanization,as a case study,this study aimed to investigate the impact of different urban spatial growth patterns on the accessibility and equity of urban green spaces.First of all,an evaluation model for the accessibility of urban green space was constructed by considering the attractiveness of urban green space and the differentiation among the search radiuses of multi-level urban green spaces,and the Gini coefficient was adopted to assess the equity of urban green space accessibility.Secondly,an integrated urban growth model was developed by incorporating the spatial autocorrelation in the pattern of urban expansion and the differences in the transition probabilities of different land use classes to urban land use.Thirdly,multiple urban expansion pattern scenarios were developed according to the aspects of growth form(sprawl or compact development)and structural pattern(monocentric or polycentric),of which the accessibility and equity of urban green space were simulated.The main findings of this study are as follows:(1)During the study period(1995-2015),dominant land-use types in Guangzhou were green spaces,arable land,and urban land.With the acceleration of urbanization,the area of urban land and other construction land has largely increased,while the area of arable land,green space,and water bodies has significantly decreased.Among them,urban land and green space showed the highest degree of dynamic,and arable land and green space had the largest area of conversion.(2)The accessibility of urban green space in the urban core area was significantly lower than in the urban peripheral area,and approximately 3.26%-16.34% of urban residents have no access to green spaces,indicating a spatial inequality of green space distribution.According to the results of scenario analysis,for the entire study area,the“compact-monocentric” and “sprawl-monocentric” scenarios showed the highest and lowest green space accessibility,respectively.In the urban core area,the “sprawl-polycentric”scenario had the highest green space accessibility,while the “compact-polycentric” scenario showed the lowest.Alike to the whole study area,the “compact-monocentric” and“sprawl-monocentric” scenarios showed the highest and lowest green space accessibility,respectively,in the urban peripheral area.(3)With regard to the equity of urban green space accessibility,for the entire study area,the “sprawl-polycentric” scenario showed the highest degree of equity and the“compact-monocentric” scenario showed the lowest.Similar to the accessibility,the urban peripheral area had the same trend as the study area,that is,the “sprawl-polycentric” and“compact-monocentric” scenarios showed the highest and lowest levels of equity,respectively.Conversely,in the urban core area,the “compact-monocentric” scenario had the highest level of equity,whereas the “sprawl-polycentric” scenario showed the lowest level of equity.In the end,urban planning strategies that aim to improve the overall accessibility and equity of urban green space were formulated according to the aspects of urban growth form and structural pattern.The findings of this study provide not only important implications for the green and sustainable development in Guangzhou but also a great reference for other cities in China.