Study On The Mechanism And Effect Of Urban Sprawl On Invironmental Pollution

As the largest developing country in the world,China has limited natural resources and prominent environmental issues.It also shoulders the difficult tasks of economic development and environmental protection.With the improvement of urbanization,the speed of urban space is obviously faster than that of population growth,and it becoming the main characteristics of China’s urban development.Therefore,exploring the mechanism and effect of urban sprawl on environmental pollution,choose a reasonable way of urban development,and reduce the negative impact of urban sprawl is of great significance to our country.It help us improve environmental pollution,realize energy conservation and build ecological civilization in China.In this paper,the relationship between urban sprawl and environmental pollution is analyzed from two aspects: the mechanism and the effect.First of all,urban sprawl affects environmental through four aspects: scale effect,structural effect,technological effect and policy effect.Second,population size variables are selected into the theoretical framework to analyze the threshold effect of urban sprawl on environmental pollution under different city scales.Third,constructing the urban sprawl index and using the fixed-effect model to demonstrate the linear relationship between urban sprawl and environmental pollution,using dynamic regression models to eliminate endogeneity,and using quantile regression model to evaluate the impact of urban sprawl on environmental pollution at different quantiles.Finally,the threshold effect model and the robustness are analyzed.The results show that:(1)Urban sprawl in China has significantly increased environmental pollution.(2)The effect of urban sprawl on the environment is affected by economic scale,industrial structure,technological development and policies.(3)In different areas,the effect of urban sprawl on environmental pollution is different.The increase of urban sprawl has the most prominent effect on the promotion of industrial wastes in the eastern region,followed by the western region and the least impact is in the central region.(4)At different quantiles,the impact of urban sprawl on environment is different.When the urban has better environmental quality,the effect of urban sprawl on environmental pollution will be more prominent than that of cities with poor environmental quality.(5)There is a nonlinear relationship between urban sprawl and environmental pollution.These conclusions have implications for changing the concept of urban development,strengthening urban environmental pollution control,and promoting the green development of cities.This paper draws the following four inspirations:(1)Advocate a compact city concept,strengthen urban planning,and control urban sprawl.(2)The eastern and western cities should accelerate the transformation of economic development mode and strive to reduce industrial pollution.(3)Correctly judge the degree of urban sprawl of different population sizes,and formulate environmental regulation policies according to local conditions.(4)we should guide residents to change their consumption concepts,enhance their awareness of environmental protection and reduce environmental pollution.The innovation of this paper is as follows:(1)Explore the nonlinear relationship between urban sprawl and environmental pollution.The existing literature focuses on directly establishing a linear model and exploring the linear relationship between the urban sprawl and environment.Based on the study of the linear relationship between the two,this paper studies the nonlinear relationship and conducts a robust test.(2)Select urban scale as entry point to explore the nonlinear relationship between urban sprawl and environmental pollution in different scale of cities.Combined with quantile regression,the differences in the effects of urban sprawl on environmental pollution at different sub-points were investigated.