Spatio-temporal Evolution Of Urban Resilience And Its Influencing Factors In The Yellow River Basin

As a complex social ecosystem,city faces the impact of many uncertain factors and risks.The accelerated urbanization process in China has brought about many reallife problems and safety hazards,which have put forward a more urgent need to enhance the ability of urban risk prevention and control and improve the level of urban resilience.As an important ecological security barrier,the Yellow River Basin plays an overall and strategic role in our economic development.However,for a long time,problems such as weak ecological background,low quality of urban development,heavy reliance on energy,low quality and low efficiency have been prominent in the Yellow River Basin,seriously restricting the sound development of cities.To effectively cope with various changes or shocks,reduce uncertainty and vulnerability in the process of urban development,and improve the resilience of cities in the Yellow River Basin are inevitable requirements for promoting ecological protection and high-quality development and realizing sustainable economic development.Therefore,it is necessary to scientifically clarify the spatial-temporal evolution of urban resilience levels in the Yellow River Basin,explore the driving factors and mechanism of urban resilience development,and build healthier,safer and more livable modern cities.By selecting 79 cities in the Yellow River Basin as the research object,this paper constructs a comprehensive measurement index system of urban resilience in four dimensions of "economy-society-ecology-infrastructure".The entropy method was used to measure the urban resilience index of the Yellow River Basin.Then,nonparametric kernel density estimation,exploratory spatial data analysis,and Dagum Gini coefficient decomposition are used to reveal the spatio-temporal evolution characteristics of urban resilience in the Yellow River Basin from the aspects of spatiotemporal differentiation,spatial agglomeration and spatial heterogeneity.The driving forces behind the horizontal spatial differentiation of urban resilience in the basin were explored by using Geo Detector.And the conclusions were drawn as follows.(1)During the study period,the urban resilience level in the basin was improved,and the absolute gap between cities in the resilience level was continuously enlarged.From the perspective of different regions,the resilience level of downstream regions and provincial cities is higher than that of other regions,while the resilience index of middle and upstream regions is lower than the average level of the basin.Among the three regions in the Yellow River Basin,the average level of resilience index in the middle reaches of the Yellow River Basin is relatively lower than that in other regions.In terms of the whole basin,Dingxi,Longnan and Shangluo are the cities with the lowest urban resilience index in the whole basin,and the resilience level has little change during the study period.(2)From different dimensions,the level of urban resilience changes to some extent in different subsystems.The economic resilience level of cities in the middle and upper reaches of the country has been increasing over time,and the difference in economic resilience level among cities has been deepening.The resilience index of ecological resilience level is low and the growth change range is not large during the study period,which is the weak factor restricting the improvement of urban resilience level in the Yellow River Basin.Infrastructure resilience shows a high north to low south distribution.The level of social resilience in the middle and upstream regions is lower than that in the downstream regions.(3)The urban resilience of the Yellow River Basin showed significant spatial autocorrelation.HH cluster areas are mainly concentrated in the central and eastern prefecture-level cities of Shandong Province.LL agglomeration type cities are mainly concentrated in Longnan,Tianshui,Pingliang,Guyuan and other places in the south of Gansu Province,Yan ’an city in Shaanxi Province,and Sanmenxia city in Henan Province.The distribution of LH cluster cities and HL cluster cities is relatively dispersed.The number of HL cluster cities decreased over time during the study period.(4)The regional differences of urban comprehensive resilience in the Yellow River Basin decreased slightly during the study period.From the perspective of intra-regional differences,intra-regional differences and changes in resilience level in the upstream region were the largest,while intra-regional differences and changes in the middle and downstream regions were small.From the perspective of inter-regional differences,the inter-regional differences between the downstream region and other regions are relatively large and the degree of difference is decreasing continuously.The difference between the middle and downstream regions is the most obvious reduction,while the difference between the upper and middle regions has little change.The supervariable density and interregional differences contribute to the regional variation of urban resilience in the Yellow River Basin.(5)There were differences in the specific effects of various influencing factors on urban resilience in the Yellow River Basin as a whole and in different regions.On the whole,land expansion is the main factor that causes horizontal spatial differentiation of urban resilience in the basin.From the perspective of different regions,land expansion and innovation level have great effect on spatial differentiation of urban resilience in the upstream.Land expansion and informatization were the most powerful factors to explain the horizontal factors of urban resilience in the middle reaches.The degree of informatization and economic scale are the main reasons for spatial differentiation of resilience of downstream cities.The two-factor interaction among all factors always has a greater impact on the horizontal spatial differentiation of urban resilience in the watershed than the single factor.