Research On The Evolution Of Urban Agglomeration Patterns On The Northern Slope Of Tianshan Mountains Based On Rasterization

Urban agglomeration is the highest spatial organization form of urban cross regional joint development to the mature stage.It refers to the urban agglomeration with compact spatial organization,close economic connection,high degree of integration and integration formed by relying on the developed transportation and communication infrastructure network in a specific region.With the continuous agglomeration of population and industry,the contradictions between population and resource allocation,production and natural environment become increasingly fierce.Therefore,it is of great significance to explore the evolution process of urban agglomeration pattern for coordinating regional development and improving man land relationship.In this paper,DMSP/OLS and NPP/VIIRS two kinds of nighttime light data are used as the basis to integrate the two kinds of data through data fitting,and the built-up area spatial scope of15 counties and cities in the northern slope of Tianshan Mountain urban agglomeration is extracted;This paper analyzes the evolution of the spatial pattern of the built-up areas in the urban agglomeration from four aspects: morphological characteristics,scale characteristics,hierarchical structure characteristics and expansion direction;Through the method of statistical data spatialization,using night light data to spatialize the GDP data of each county and city,this paper analyzes the evolution of economic spatial pattern of urban agglomeration.The main results are as follows:(1)Obtain continuous night light data in the study area through the integrated method constructed on the two types of night light data of DMSP/OLS and NPP/VIIRS.On this basis,combined with statistical data,the threshold method is used to extract the spatial distribution status of the rasterized built-up areas of the 15 counties and cities in the threephase urban agglomeration in 2000,2010,and 2019,and the statistical data is used for accuracy testing.The overall deviations of the three phases were 1.3%,0.79%,and 0.6%respectively.High-precision images were used to visually judge the spatial extent of the built-up area,and the final results met the research requirements.(2)Based on the extraction results of the built-up areas of the counties and cities in the urban agglomeration,the results show that the urban agglomeration expanded through a combination of external expansion and internal and marginal filling from 2000 to 2010,and the spatial compactness changed little,and the built-up area The increase was 60.2%,and the expansion of built-up areas in Shihezi City was relatively large.From 2010 to2019,the development speed of urban agglomerations accelerated,mainly through external expansion,and the space compactness was significantly reduced.The built-up area increased by 66.2%.The expansion of the built-up area in Changji City and Wujiaqu City was relatively large;during the study period,Changji City The establishment of the Municipal High-tech Zone and the Qinghu Ecological Development Zone in Wujiaqu City has significantly changed the expansion direction of the built-up areas in the two places,and the expansion of the remaining counties and cities is relatively balanced.(3)Construct a light index by integrating night light images,select the best light index,and perform a spatial simulation of the GDP of the secondary and tertiary industries of the urban agglomeration,and combine the LUCC data to perform a spatial simulation of the GDP of the primary industry of the urban agglomeration,and finally obtain the GDP space of the urban agglomeration The results of the distribution show that the output value of each industry in the urban agglomeration is distributed in the main nodes of the traffic line between the counties and cities have obvious agglomeration characteristics."Wu-Chang-Shi-Ke" is a key development city,and its economic scale is relatively large.During the study period,the spatial distribution of urban agglomeration GDP showed a decreasing divergence from the center of the city,and as the size of the city became larger,the radiation range changed The overall output value continues to increase,the output value per unit area continues to increase,and the prominent part of the output value of the key development cities is becoming more and more obvious.