Spatial Morphology Evolution Analysis Of Chengdu City Based On Luminous Remote Sensing

Since the reform and open policy,our country's economic construction and urbanization development is rapid,but regional social and economic development and environmental protection exist obvious imbalance,this is an urgent need to by examining macro human activity impact on large scale,especially through detailed and comprehensive understanding of the urban expansion of space and time distribution rules to correct understanding of the current our country faced the crisis of unbalanced regional development and environmental protection.However,it is very difficult to obtain large-scale urban expansion data by conventional methods,and the data of night light can provide effective data support for the study of large-scale urban expansion and its driving mechanism.In China's Sichuan province Chengdu city as an example,the GIS technology,extract the NPP from 2013 to 2017-VIIRS data of Chengdu urban spatial information,from 2013 to 2017 of Chengdu 20 county(district)level administrative within the scope of the extraction and analysis of the urban space expansion,summarized a set of urban areas,and extraction methods of Chengdu,Chengdu is analyzed urban space form,extension rate,etc.Combined with the statistical analysis method,the driving force and mechanism of urban space expansion in Chengdu are analyzed.The main results of this study are as follows:1.NPP-VIIRS data were selected as the main data in the study.In terms of noise reduction,logarithmic transformation was used to reduce the data distribution,weaken the difference of data radiation value,and reduce the distribution range of data radiation value.The logarithmic method has a better imaging effect on luminous remote sensing data,and the continuous and clear imaging is suitable for the analysis of urban space.2.The urban spatial form of Chengdu was extracted by threshold method on Arc GIS,combining the urban built-up area,urban construction land area and relevant statistical data.And verify the positive correlation between the extracted urban area and the development of urban space.It indicates that the faster the spot growth rate of luminous remote sensing image is,the faster the expansion of the city will be.3.Based on the latest luminous remote sensing image,the current urban spatial form of Chengdu is analyzed as a star-shaped city.By comparing with the general regulations of urban development boundary line and construction land scope published by the government,it is verified that the urban space of Chengdu belongs to the star-shaped city,which conforms to the urban spatial structure of "one district,two belts and six corridors" and has the spatial characteristics of "double center,double axis and multi-point".4.This paper analyzes the driving forces of the urban spatial evolution of Chengdu,mainly from five aspects: natural geography,social economy,urban transportation,history and humanity,and major policies.5.TOD mode was discussed by comparing the spatial morphology of Chengdu city with the fit relationship of rail transit,and combining with the actual TOD project of Chang Gong Yan.TOD mode will be beneficial to the optimization and promotion of the spatial form of Chengdu in the future.