Evaluation And Optimization Strategy Of Mianyang City Based On The "Pressure-State-Response" Model

City as a social and economic development,dense population distribution,resource consumption and environmental pollution concentration area and the important carrier of regional sustainable development,in the environment of rapid population growth and expanding urban scale,urban development by urban comprehensive constraints increasingly obvious,and cause the attention of all sectors,how urban comprehensive carrying capacity and sustainable development,not only related to urban subsequent development,is also related to its regional sustainable development goals.Taking Mianyang city and districts and counties as the research object,the "pressure-state-response"(P-S is constructed based on the P-S-R)model,firstly calculate the index weight of Mianyang City and districts and counties,and then calculate the pressure,state,response and comprehensive bearing capacity index of cities and counties according to the weight.According to the calculation results,the spatial and temporal evolution process of the cities and counties,the global and local correlation and influencing factors of the cities and counties from 2009 to 2019 are analyzed,and finally the relevant strategies to optimize the comprehensive carrying capacity are put forward.Through the analysis,the following main conclusions are obtained:(1)the pressure,state and response index of Mianyang city and all districts and counties generally fluctuate.Among them,the pressure index increased the most by 25.03% and the response index by 2.44%;among all districts and counties,Fucheng District had the highest increase of 12.64%,Beichuan County the lowest by 0.31%,Pingwu County 3.90%,3.70%,only Pingwu County showed negative growth of-3.63%,other districts and counties showed positive growth,and Jiangyou City had 4.35%;(2)the comprehensive carrying capacity index of the city and districts and counties increased.The comprehensive bearing capacity index of Mianyang city increased by 44.38%,from low to high bearing,the bearing index of Fucheng District increased by 19.81%,from medium to high bearing,Youxian,Santai,Anyi and Jiangyou from low to medium bearing,Yanting,Beichuan,Pingwu and Zitong,still low bearing,with central high and low distribution in space;(3)low spatial concentration.In the global autocorrelation,the Moran’s I was negative in 2010 and 2016,Index values for the remaining years were mostly positive,But the values are relatively small,Thus shows that the comprehensive carrying capacity presents a trend from discrete to aggregate in the global spatial development,However,the aggregation degree was relatively weak,Low overall degree of correlation;Comprehensive bearing capacity in the local autocorrelation,In Fucheng District,Youxian District and An County have passed the significance test more often than in other districts and counties,The spatial aggregation effect was significant,It shows that these three districts and counties themselves have a high carrying level,It also has a strong impact on the surrounding districts and counties,The comprehensive carrying capacity of the other districts and counties is weak,Low degree of spatial aggregation;(4)The driving force affecting the change of the comprehensive carrying capacity of Mianyang city and various districts and counties is different.The main driving factors of Mianyang city are urbanization rate,GDP and output value of secondary and tertiary industries,while the other index factors are not significant.The driving force of the urbanization rate is the common factor of the counties,including the other counties,indicating that social development and economic improvement are the main driving force to promote urban comprehensive carrying capacity.