Study On The Spatial And Temporal Evolution Of The Interaction Between Urbanization And Ecological Environment In Hebei Province

Urbanization is the only way to promote social and economic development and realize China’s modernization.However,population growth,resource consumption,regional expansion and other issues also bring practical pressure to the ecological environment,which to some extent restricts the development of social economy and urbanization.Therefore,quantitative discussion of the interaction between urbanization and ecological environment is conducive to grasping the development status of urbanization and ecological environment,and provides a reference for the balanced coordination of urbanization and ecological environment.Taking Hebei province and each prefecture-level city and county as the research area,constructed the index system for evaluating the comprehensive level of urbanization,calculated the urbanization index,extracted four important indicators reflecting greenness,dryness,humidity and heat based on Moderate Resolution Imaging Spectroradiometer(MODIS)data from2008-2019,and obtained Remote Sensing based Ecological Index(RSEI)by principal component analysis.Based on this,analyzed the trend of the integrated level of urbanization and ecological environment at the provincial,municipal and county administrative scales from 2008 to 2019.Finally,the coupling coordination degree model and Tapio decoupling model were used to quantitatively calculate the coupling coordination and decoupling index,and the spatio-temporal evolution characteristics of the interaction between urbanization process and ecological environment were analyzed.The main conclusions are as follows:(1)The comprehensive level of urbanization among different scales showed an upward trend,the provincial urbanization comprehensive index increased from 0.080 in 2008 to 0.843 in 2019.The contribution rate of population and spatial urbanization showed a downward trend,while the contribution rate of economic and social urbanization showed an upward trend.The urbanization types of cities at various levels were mainly high urbanization areas and medium urbanization areas,with the spatial distribution showed a pattern of "high in the middle,low in the north and south".The degree of urbanization spatial agglomeration among county-level units showed a downward trend,and the urbanization level gap was gradually narrowing.(2)The comprehensive level of ecological environment between different scales showed a gentle change,the average value of provincial RSEI decreased from 0.637 in2008 to 0.569 in 2019.WET,which plays a positive promoting role,showed an upward trend,and NDVI,NDBSI and LST showed a downward trend.The excellent level areas were concentrated in the northern Yanshan Mountains and the western Taihang Mountains.The spatial concentration degree of ecological environment among county level units showed an upward trend,and the quality of ecological environment in the intermountain basin and Bashang Plateau in northwest Hebei Province has gradually improved.(3)The coupling coordination degree of the whole province increased from 0.475 in 2008 to 0.832 in 2019,stepping from the transitional development stage to the coordinated development stage.The coupling coordination type of cities at all levels had been upgraded from a mild imbalance recession type to a medium coordinated development type or a good coordinated development type.The degree of spatial concentration of coupling coordination between county-level units showed an upward trend,and the proportion of good coordinated development type and intermediate coordinated development type of county level units tended to be 1:1.6.The type of coupling coordination among Shijiazhuang,Langfang and Qinhuangdao urban areas took the lead in achieving high-quality coordinated development.(4)The decoupling types of urbanization and ecological environment between different scales mainly showed three states: strong decoupling,weak decoupling and expansionary negative decoupling.The cities at various levels in the rapid development stage of urbanization mainly showed a negative effect on the ecological environment,which tended to weaken.The decoupling relationship of each county and city coexists with negative decoupling,decoupling and connection.In the early stage,the coercive effect of urbanization on the ecological environment continued to emerge,and in the later stage,the ecological environment and urbanization growth rate were equivalent,each county and city gradually entered into active urbanization.