Coupling Coordination And Mechanism Of Urbanization And Land Use Efficiency In Gansu Section Of Yellow River Basin

The Yellow River Basin is an important ecological security barrier and economic development zone in China,and the Gansu section of the Yellow River Basin has special socio-economic conditions,diverse regional types and complex ecological environment.Under the new historical opportunity of ecological protection and high-quality development strategy in the Yellow River Basin rising to a major national development strategy and the field of urban and rural construction in the Yellow River Basin becoming an important battlefield in high-quality development,the demand for land resources for social and economic development is still very strong,so it is of great significance to study the coupling coordination and mechanism of urbanization and land use efficiency in the Gansu section of the Yellow River Basin to alleviate the contradiction between people and land,promote sustainable development and promote high-quality development.In this study,the Gansu section of the Yellow River Basin was selected from five periods,including 2000,2005,2010,2015 and 2020,and comprehensively used Arcgis,Stata and other software to reveal the temporal and spatial evolution of urbanization development level in the Gansu section of the Yellow River Basin through the entropy method and standard deviation ellipse method.Through the land use transfer matrix,the temporal and spatial evolution characteristics of land use structure in the urbanization process of Gansu section of the Yellow River Basin were revealed.Based on the input-output perspective,the spatiotemporal evolution of land use efficiency in the Gansu section of the Yellow River Basin was explored by data envelopment analysis(DEA).The coupling coordination model was used to analyze the coupling relationship and coordination status between urbanization and land use efficiency in the Gansu section of the Yellow River Basin.The panel vector autoregressive model(PVAR)was used to explore the dynamic interaction between urbanization subsystems and land use efficiency,and summarized its mechanism.The following conclusions are drawn:(1)Temporal and spatial evolution of urbanization development.During the study period,the urbanization development level of the Gansu section of the Yellow River Basin showed a continuous upward trend,and the urbanization development level increased rapidly before 2010,and the growth rate decreased after 2010.The spatial pattern distribution of urbanization development level is mainly low-level area and general horizontal area,high-value areas are mainly concentrated in Lanzhou City and surrounding counties,and low-value areas are located in Linxia Prefecture and other counties.The spatial pattern evolved significantly,and the center of gravity of the urbanization development level index shifted to the southeast,and the agglomeration of urbanization development level increased during the study period.The scores of each subsystem showed an increasing trend,and the high-value areas of population urbanization,economic urbanization and social urbanization subsystems were similar to those of comprehensive urbanization,and the high-value areas of ecological urbanization were mainly distributed in Gannan and Qingyang areas.(2)Spatial and temporal evolution of land use.(1)From 2000 to 2020,the area of cultivated land and unused land in the Gansu section of the Yellow River Basin decreased,and the area of grassland,construction land,forest land and water area increased to varying degrees.From the perspective of the spatial distribution of land use transfer,the transfer of cultivated land to grassland mostly occurred in areas with better ecological functions.The transfer of cultivated land to construction land mostly occurs in areas with high levels of socio-economic development.(2)During the study period,land use efficiency continued to rise,and the land use efficiency increased rapidly before 2010,and the growth rate decreased after 2010.The spatial pattern distribution of land use efficiency was mainly distributed in relatively inefficient areas,and the land use efficiency areas were mainly distributed in Lanzhou City,which has a high level of urbanization development,and in 2020,Zhengning County was the only inefficient area in the study area.The spatial pattern evolved significantly,the center of gravity of the land use efficiency index shifted to the northeast,the standard deviation elliptical major axis increased and the minor axis decreased during the study period,and the directionality of the "southwest-northeast" distribution increased.(3)Coupling and coordination analysis of urbanization and land use efficiency.During the study period,the coupling degree and coupling coordination degree of urbanization and land use efficiency in the Gansu section of the Yellow River Basin showed an upward trend,and the two systems as a whole showed the unbalanced development characteristics of "high coupling and low coordination".From the perspective of spatial distribution pattern,the coupling type was mainly running-in and high-level coupling,and from east to west,the coupling degree between urbanization and land use efficiency in the Gansu section of the Yellow River Basin gradually weakened.The coupling coordination types were mainly borderline and mild offset,and the coupling coordination degree from east to west gradually weakened.(4)Analysis of the mechanism of urbanization and land use efficiency.The impulse response results show that there is a two-way interaction between each urbanization subsystem and land use efficiency.The improvement of economic urbanization will promote the improvement of land use efficiency,and the improvement of population urbanization,social urbanization and ecological urbanization will inhibit the improvement of land use efficiency in the short term,and the improvement of land use efficiency will promote the development of population urbanization,economic urbanization,social urbanization and ecological urbanization.The variance decomposition results show that the contribution rate of urbanization subsystem to the change of land use efficiency is economic urbanization>social urbanization> ecological urbanization > population urbanization,and the impact of land use efficiency on the urbanization subsystem is economic urbanization>population urbanization> social urbanization > ecological urbanization.