| Urban ecological space is crucial to the sustainable development of cities and the improvement of human well-being.The expansion of urban built-up areas and the rapid growth of population have led to the fragmentation of landscape and the decline of ecosystem function,and caused a series of ecological and environmental problems.Urban ecological space is an important ecological infrastructure and carrier of naturebased solutions,the supply level,resource distribution pattern,actual utilization status of urban ecological space and the equity of people’s access to urban ecological space services are receiving increasing attention.China’s coastal cities are economically developed and have a high level of urbanization,the unique sea and land ecological environment makes them have marine and land ecological spaces.In the rapid urbanization period,the spatiotemporal characteristics,driving factors,and temporal characteristics of the ecological space supply equity in China’s coastal cities are still not clear.The systematic research on the ecological space of coastal cities can provide scientific support for the overall planning of marine and land ecological space and the optimization of territorial space planning,which is of great significance to improve the life quality of residents and promote sustainable urban development.This study selected 53 coastal cities in China as the study domain.Firstly,taking the urban built-up area as the center,extracted the marine,land and total ecological space that urban residents can reach within half an hour of walking,public transportation and driving from the year 1990 to 2015,and counted the stock of ecological space to characterize the ecological space availability.Secondly,the Gaussian-based two-step floating catchment area method was applied to evaluate the ecological space accessibility of coastal cities.Thirdly,combined with POI data,based on a questionnaire survey and big data analysis technology in Python,we constructed the ecological space realization indicator to evaluate the utilization status of ecological space in coastal cities in 2015.Fourthly,the spatial econometric model was used to reveal the driving factors and spatial spillover effect of the ecological space availability and accessibility,and the geographical detector was applied to explore the influencing factors of the ecological space realization indicator.Finally,this paper applied the concentration curve and concentration index to explore the equity of ecological space supply among cities.The main findings are as follows:(1)From the year 1990 to 2015,the marine,land and total ecological space availability in coastal cities showed an upward trend.The high availability of land,total ecological space and marine ecological space under the mode of public transportation and driving are concentrated in the coastal city of Zhejiang and Fujian,and the low availability of land area and total ecological space are concentrated in the Bohai Rim region.(2)The land and total ecological space accessibility of coastal cities in China showed a downward trend.The marine,land and total ecological space accessibility in southern cities are generally higher than those in northern cities.The land area and total ecological space accessibility are inversely proportional to the size of cities.(3)The realization rate and score of marine,land,and total ecological space are in direct proportion to the size of the city.With the increase in travel distance,the differences in the realization quantity of marine,land,and total ecological space among coastal cities are gradually reduced.(4)The expansion of urban built-up areas will lead to the improvement of the availability and accessibility of marine,land,and total ecological space in coastal cities.With the increase in travel distance,the most important factor affecting the land and total ecological space realization quantity change from infrastructure variables to physical geography variables.(5)The availability and realization quantity of marine,land and total ecological space in economically developed cities are always higher than those in economically underdeveloped cities,while the accessibility of three types of ecological space is always lower than those in economically underdeveloped cities.With the increase in travel distance,the fairness of availability of the three types of ecological space gradually increases,and the fairness of accessibility of land and total ecological space gradually decreases. |
