Analysis On Process Of Temporal And Spatial Evolution And Driving Factors Of Urban Built-up Area Expansion In The Yellow River Basin Based On Nighttim Light Data

Since the reform and opening up,China’s economy has developed rapidly and the level of urbanization has been increasing year by year.With the continuous improvement of the level of urbanization,the scale of urban land has been increasing year by year,the urban space has been expanding,and the area of urban built-up area has been expanding day by day.Studies have found that different city proper expansion mode,most cities in the pursuit of economic benefits,ignore the social benefits,ecological benefits and environmental benefits,the expansion of the city proper is spread type is given priority to,namely "booth pie" model,caused the waste of urban land,environment worsening and ecological imbalance,lack of staying power for the sustainable development of urban economy and a series of problems.How to make intensive use of urban land,change the past "spread the pie" expansion mode,do a good job in ecological protection,and promote high-quality economic development has gradually become a research hotspot in the field of geography.The above issues have also attracted great attention from the national government.From August2019 to October 2021,General Secretary Xi Jinping visited Gansu,Inner Mongolia,Qinghai,Ningxia,Shanxi,Shaanxi,Henan and Shandong provinces along the Yellow River.On September 18,2019,general secretary of xi jinping hosted in zhengzhou Yellow River basin ecological protection and high quality development forums and delivered an important speech,this marks a new situation was created in the Yellow River management and protection,the Yellow River basin has entered a new stage of development,ecological protection and high quality development of the Yellow River basin,has become the focus of attention of the party and the state.It concerns the country’s overall development strategy.Therefore,this study selected the Yellow River basin as the study area,analysis of the Yellow River city proper expansion space-time evolution characteristics and driving factors of urban land use pattern of identification of the Yellow River basin,adjust the structure of land use,improve the efficiency of land use,promote the sustainable and healthy development of the Yellow River basin,it is of great significance.This study is based on sustainable development theory,urban spatial expansion theory and land intensive use theory.DMSP-OLS,NPP-VIIRS nighttime light data,statistical yearbook data of each province,etc.Using gravity transfer model,common edge measure model,grey relational degree model and other research methods.Taking 78 prefecture-level cities in the Yellow River Basin as research objects,this paper analyzed the spatial and temporal pattern,gravity center shift,expansion mode and direction of urban builtup area expansion and the driving factors of urban built-up area expansion in the Yellow River Basin from2000 to 2018.The results show that:(1)The urban built-up area of the Yellow River Basin continues to expand,increasing from 0.3,500 km~2 in 2000 to 10,600 km~2 in 2018.(2)The urban built-up area expansion of the Yellow River Basin not only has significant difference in the upper,middle and lower reaches,but also has significant difference between provincial and non-provincial cities.(3)The total area,net increase area,growth rate and expansion intensity of urban built-up areas in the Yellow River Basin from 2000 to 2018 showed a trend of "from northwest to southeast".(4)From the perspective of expansion mode,urban builtup areas in the Yellow River Basin are mainly sprawled,accounting for more than 90%.(5)In terms of expansion direction,the expansion of urban built-up areas in the Yellow River Basin from 2000 to 2018 was mainly east-west,supplemented by north-south.(6)The expansion of urban built-up areas in the Yellow River Basin is influenced by many factors,and the correlation degree between the total population at the end of the year,the actual urban road area at the end of the year and the GDP is the highest,which are the main driving factors for the expansion of urban built-up areas.Studied the expansion of the Yellow River city proper and the driving factors,clarify the Yellow River city proper expansion characteristics and main influence factors of urban land utilization for the Yellow River,the high quality and economic development,ecological environment protection for reference,can also be used for the relevant government departments to formulate the Yellow River basin sustainable development with high quality,provide a basis for scientific decision-making.At the same time,this study can also provide scientific guidance for adjusting the development mode of land use,reasonably saving urban land,protecting urban ecological environment and promoting high-quality economic development in areas with the same or similar background as the Yellow River Basin.