| The Yangtze River Economic Belt connects the three major regions of China’s east,middle,and west.It is a coordinated development belt of interaction and cooperation between the east,middle and the west.It is a pioneering demonstration belt for the construction of ecological civilization.To give full play to the radiating role of core cities,to create three economic growth poles in the upper,middle and lower reaches of the Yangtze River Economic Belt,and to promote the concept of ecological priority and green development is an important task to promote the high-quality development of the Yangtze River Economic Belt.Therefore,this paper selects the core cities of Chongqing,Wuhan,and Shanghai in the upper,middle and lower reaches of the Yangtze River Economic Belt as the research areas.First,it establishes an urban ecosystem health evaluation system based on the DPSIR model,and evaluates the ecosystem health of the three core cities in the Yangtze River Economic Belt from 2013 to 2017.The status is dynamically evaluated,and then the main factors hindering the healthy development of the urban ecosystem are determined through the obstacle factor diagnosis model,and the GM(1.1)gray prediction model is used to predict the health status of the three core urban ecosystems,and derive the health status of the three core cities in the future,finally,based on the healthy development trends of the three core urban ecosystems and the main obstacles,corresponding development strategies are proposed to promote the sustainable development of the core urban ecosystems and provide a new perspective for the policy-making of urban planning managers.The main research conclusions are as follows:(1)From the perspective of the comprehensive evaluation index of urban ecosystem health,Chongqing’s comprehensive health index is relatively high,and the overall health level is “healthy”,followed by Wuhan.The health level status is“sub-healthy”,and Shanghai’s comprehensive health index is relatively low,from2013 to 2015,the health level was "unhealthy",from 2016 to 2017,the health level was "sub-healthy".Secondly,from the subsystem level health index,Shanghai is mainly the state layer and the impact layer health index relatively low.In the past five years,the health index of the pressure layer and the influence layer in Wuhan has shown a downward trend,which needs to be paid attention to.In the past five years,the health index of the pressure layer has declined in Chongqing.In the spatial comparison analysis,from 2013 to 2017,Chongqing and Wuhan have the highest comprehensive evaluation value of urban ecosystem health,followed by Shanghai.From 2013 to 2015,Shanghai was in an unhealthy state,Wuhan was in a sub-healthy state,and Chongqing was in a healthy state.From 2016 to 2017,Shanghai and Wuhan were in a sub-healthy state,and Chongqing was in a healthy state,indicating that the health of the urban ecosystem in Shanghai has improved significantly and improved rapidly.(2)From the analysis of the main obstacle factors at the subsystem level,the order of the number and frequency of the main obstacle factors at the subsystem level in Shanghai is pressure layer>driving force layer>response layer>influence layer>state layer,and Wuhan city is response layer=state layer >Influence layer>Driving force layer=pressure layer,Chongqing is the pressure layer>influence layer>state layer>response layer>driving force layer;as far as the main obstacle factors of the index layer are concerned,the main obstacle factors of the index layer in Shanghai in 2013 the ranking of obstacles in the city is urban per capita housing area,industrial wastewater discharge,and acid rain frequency occupy the top three,becoming domestic waste discharge,total domestic water consumption,and the number of college students in 2017.Wuhan City’s natural population growth from2013 the rate of green area in parks,and the rate of good air environment quality have been transformed into economic density in 2017,green area in parks,and natural population growth rate.Chongqing has changed from the tertiary industry’s share of GDP in 2013,the output value of agriculture,forestry,animal husbandry and fishery,and the foreign exchange income of international tourism.It is the ratio of tertiary industry to GDP in 2017,per capita social electricity consumption,and output value of agriculture,forestry,animal husbandry and fishery.(3)The prediction results of the ecosystem health status of the three core cities in the Yangtze River Economic Zone show that the predicted value of Shanghai in 2021 is 0.869565,Wuhan City is 0.721117,and Chongqing City is 0.934323.The three cities are in the direction of future ecosystem health,Chongqing is still the best and is in a very healthy state.Shanghai has surpassed Wuhan to rank second and is in a very healthy state.Wuhan is still developing steadily and in a healthy state. |
