Sustainability Evaluation Of Regional Complex Ecosystem Under Urbanization Develpoment

Urbanization has played a positive role in promoting China's economic development and improving people's living standards.However,while China is rapidly urbanizing,it has also exerted tremendous pressure on the ecological environment.The continuous expansion of cities indicates that it is necessary to establish a new management model for the coupling of socio-economic-natural complex ecosystems.How to achieve the effective evaluation of the social economy and natural tresources in the complex ecosystem will be an important guarantee for the smooth development of China's sustainable development under the new urbanization process.Based on the emergy analysis method and the unit area equivalent method,the article combined the socio-economic-natural complex ecosystem theory.Taking Yantai City,an eastern coastal city in Shandong Province,as the research object,the sustainable development of the composite ecosystem in Yantai City from 2005 to 2016 was evaluated.and the main factors affecting the sustainable development of the regional composite eco-economic system in Yantai City were explored.The main findings are as follows:(1)Social Subsystem:Yantai has few local renewable resources.The energy and materials needed for social development mainly depend on local non-renewable resources,energy and materials imported from other places.It can be seen that Yantai relies heavily on non-renewable resources and imports.In 2005-2016.the total energy use(U)of Yantai City continued to rise,from 1.18E+23sej in 2005 to 3.45E+23sej in 16 years;the use of natural resources(Rcap)could be updated by everyone.The amount gradually decreased from 5.13E+15sej in 2005 to 5.03E+15sej in 16 years;while the use of non-renewable natural resources(Ncap)increased gradually.from 9.43E+15 sej in 2005 to 16 years.The 2.55E+16 sej:the emergy use intensity(ED)increased from 8.61E+12sej/m2 in 2005 to 2.53E+13sej/m2 in 15 years.but the emergy intensity was not high compared to other cities.(2)Economic subsystem:Yantai City's development in recent years is in arelatively stable state.Compared with other developed regions,the competitiveness is at a medium level and needs to be improved.In 2005-2016,electricity consumption increased from 7.57E+21sej in 2005 to 2.64E+22sej in 16 years,However,the ratio of the power emergy value to the total emergy value is below 10%.:The ratio dropped from 4.75E+12Sej/$ in 2005 to 3.32E+12sej/$ in 16 years.indicating that the overall economic development level of Yantai City is slightly higher than the national level.but it is still signiticantly lower than other developed cities in the couintry:The emergy invesment rate rose from 0.42 in 2005 to 0.76 in 16 vears,which is hizher than the national average of the emergy investment rate,but still lower than other developed cities in China.(3)Natural subsystem:The utilization rate of local renewable resources isgradually reduced.which increases the utilization rate of non-renewable resources:The change in the type of land use structure has led to a gradual reductionin the value of natural ecosystem services,and has created tremendous ecological environmental pressures for the future sustainable development of natural system environments.The self-sufficiency rate(ESR)decreased from 0.80 in 2005 to 0.62 in 16 years;the environmental load rate increased from 2.55 in 2005 to 9.39 in 16 years;the Energy Sustainability Index(ESI)fell from 1.32 in 2005 to 0.24 in 16 years;the ecosystem service value(ESV)decreased from 3.30×104 million in 2005 to 3.14×104 million in 2015.Accordinu to the research results of this paper,it is suoggested that the industrial chain can be optimized by optimizing the industrial structure of renewable resources and non-renewable resources,and adjusting the input-output ratio of local economic resources:optimizing land use structure.preserve the cultivatedland and forest land area.pay attention to the sustainability of the economy and the environnment,avoid the ecological deficit.and make it develop towards the sustainabilitv of local transformation.and take the "green.open,sustainable development" city complex ecosystem roads.