Research On Steel Stock Of Urban Building And Transportation Infrastructure Based On The Fusion Method Of Nighttime Light And Material Flow

Steel is one of the most important metal resources in the world.It is the basic material for the normal operation of urban ecosystems.It plays an important role in the social progress,economic development,resource utilization and environmental protection of the city.There is a linear relationship between DMSP/OLS night light brightness and iron stock in urban infrastructure.By using the regression equation between night light brightness and iron stock,the iron stock in the Chinese prefecturelevel cities is estimated.And the STIRPAT extended model is established to analyze the main reasons affecting the urban iron stock.In this paper,the iron stock data of prefecture-level cities in China are obtained,and the influence of some social and economic factors,meteorological conditions and urban spatial form factors on the urban iron stock is analyzed by STIRPAT model.The paper's study of contents and its results are listed below:(1)By used statistical data,the paper has analyzed the composition of the province iron stock in China and the temporal and spatial variation characteristics of iron stock from 1995 to 2013.The results show that the province iron stock is mainly composed of iron and steel materials in the housing construction,the municipal underground pipe network,the highway and the railway transportation facilities.The temporal and spatial changes of iron stock in each province are related to its economic development level.(2)Based on the linear relationship between DMSP / OLS night light data and urban infrastructure iron stock,this paper has estimated the iron stock data of China's prefecture level cities for the first time,by using the established regression equation between night light and iron stock,and completed the research on the temporal and spatial changes of iron stock of China's prefecture level cities.The results show that the urban iron stock in the cities of the Beijing-Tianjin-Hebei,the Yangtze River Delta,and the Pearl River Delta have shown the trend of urban iron stock concentration in the research period.The urban iron stock in central regions cities,such as Wuhan economic circle and Zhengzhou Economic Circle,have shown a feature of spotted distribution that show a trend of gradual expansion with economic development.The urban iron stock in the western regions cities have shown the lower level which is influenced by the national policies and have shown that the characterized of a very high annual change rate.(3)By established the model of the STIRPAT environmental impact assessment model,this study has selected that the economic indicators such as the output value of the secondary industry,the GDP,and the population(P),the climate indicators such as the heating degree days(HDD),and the urban morphology indicators such as similar adjacent percentage(Pladj)to study the driving force of urban iron stock.This paper has constructed the model of the STIRPAT to assess of driving factors of the iron stock.By calculated of the least square method,the model has finally obtained to evaluate the driving factors of the iron stock in Chinese cities.The driving force analysis results show that the secondary output value,the GDP,the population,the heating degree days(HDD)have a positive impact on urban iron stock which is promote the accumulation of urban iron stock.For every 1% increase in population,urban iron stock will increase by 0.289%;for every 1% increase in GDP,urban iron stock will increase by0.209%.while the index of similar adjacent percentage(Pladj)has a significant negative impact on urban iron stock which is shown that the degree of urban construction land agglomeration is the higher,the abatement effect to the urban iron stock is the less.For every 1% increase in the similar adjacent percentage(Pladj),the urban iron stock will decrease by 2.431%.