Research On Environmental Issues Of Urban Development In China

City is a highly civilized form of settlements created by humankind. The developments of economy and society as well as the industrialization have accelerated the pace of urbanization. Meanwhile, the developments of cities have also resulted in many pressures and challenges in resources and enviroments. The problems of urban environment have become a main factor which has prevented the sustainable development of economy and society. Urban development is a complex dynamic process and has many influence factors. Not only can it represent the change of regional demography, but also reflect the upgrading of industrial structure, the economic developing level, and the life quality of people. The contradiction between economic growth and environment which has appeared in the developed countries for hundreds of years has emerged intensively now in cities of China as in this rapid developing period. Environmental problems in Chinese cities are characterized by stage and structure. For the differences in economic level and developing mode, the representation of environmental problems in different Chinese cities varies, and the influence mechanism differs correspondingly. Thus, it is of great theoretical and realistic significance to research the environmental problems in the cities, in the background of high-speed industrialization and urbanization.This paper mainly focuses on the environmental problems of Chinese cities in special developing stages, the contents being unfolded by analyzing the characteristics of the problems. The pollution level of China is higher than the average value of the world. The tremendous pressures of urban environment come from the growth mechanism of both population and economy, as well as the feature of urbanization. Being in the background of industrialization and urbanization, the unbalanced economic development and polluting emission in different regions are the main reasons for the dilemmas of environmental problems in Chinese cities. There are many factors that can influence urban environment, mainly reflected in three aspects: scale, structure and economic level. From the view of urban scale, as the development of marketization, more and more capitals and technologies will be centralized in cities; while the expansion of cities will lead to more requires of raw materials, and more contaminations as well. A moderate city size is advantageous for intensively dealing with pollutions, while an oversized one results in the rise of external costs. Urban development scale contains many factors such as population and land-using, in which the population size plays a more important role in China. Therefore, based on the intercept-fixed coefficient-varied model, the contribution rate of non-agricultural population size in prefectural-level and upper cities to the urban environment has been analyzed in this paper, so as to reflect the influence of urban development scale on urban environment. The contribution to the pollution of urban environment can be greatly varied depending on the population size. Generally speaking, the pollution contribution rate is positive in big cities, which means the expansion of population size will worsen the environmental pollution. The pollution contribution rate is negative in smaller cities, indicating that a proper increase in population size is beneficial to the environmental treatment, conversely. This critical point is about1,000,000. As a result, the scale of big cities and their population increasing speed should be controlled, and the migration to the smaller cities around, as well as satellite cities, should be encouraged, so as to relieve the internal developing pressure in big cities.From the view of industrial structure, the heavy tendency exists in the entire industry of Chinese cities. As important components of heavy chemical industry, steel industry and non-ferrous metals industry are the main resources of environment pollutions. Meanwhile, the development of these industries requires more from energy industries such as electricity, resulting in not only rapid developing of electricity and even coals around the cities, but also serious pollutions as well. The industrial structure is an important representation of urban developing structure. In this paper,31provincial capitals and municipalities of China were set as research objects, with pollutions of water, solid waste and air as environmental index of corresponding cities, to build a non-linear regression model of industrial structure and environmental pollution, so as to analyze the effects of urban developing structure on urban environment. The polluting degree of a city can be affected by its industrial structure and pollution control capability. It can be seen obviously form data that, the rise of proportion in heavy industry has resulted in almost20times of exponential increase in environmental pollution degree. It is much faster in the speed of environmental polluting exacerbation due to the development of intensively polluting industries, than the speed of restoration by upgrading controlling capability after pollution. Therefore, the mistake of "polluting first, treating later" should never be made again by developing countries. To restrict the development of the intensively polluting industries, to encourage high-technology industries and to upgrade pollution control capability, are the important methods to ameliorate the urban environmental quality.From the view of economic level, coupling relationship exists between urban environment and economic developing level. In this paper, a model of coupling coordination degree has been employed, to positively analyze the coordinating situation of environment and economy in260cities of China. It is disclosed that the coordinating situation of environment and economy are better in provincial capitals and tourist cities, most of which are distributed in the east. Imbalance has emerged between more developed regions and undeveloped regions, the coordination degree of former of which becomes higher, and the latter still lower. The coordination types for most prefectural-level and upper cities in China are proved to be excessive reconcile class.As an integrative analysis, a multiple regression equation has been established to inspect the compositive influences of various factors on urban environment. The gross regional product per capita in economic variables, total industrial output value; non-agricultural population in scale variables, urban road area per capita; GDP proportion of tertiary-industry in industrial variables, GDP proportion of secondary industry; the utilization ratio of wastes in technical variables make impacts on the pollution of urban environment. At the present stage, the greatest negative impacts on urban environment come from the industrial structure. The negative influences of proportion increase in secondary industry are stronger than in tertiary-industry. Demographic factors do have influences on the pollution of urban environment, but the influences are relatively smaller. Urban environment can be effectively improved by the expansion of urban built-up areas and the increase in utilization ratio of wastes. However, on the present condition, the expanding space of urban built-up areas is very limited. Even if more spaces can be gained, the expansion of urban areas still means the extension of traffic distance and rise in transporting costs, which may cause more serious air pollutions. Therefore, to improve the comprehensive utilization ratio of wastes is a very important way to reduce the pollution of urban environment.Wuhan is one of the largest cities in central China. In this paper, an aggregative index of urban development has been built through the composite index method. Based on the data of temporal series during20years, the interaction relationship of urban development and urban environment has been longitudinally researched, with the conclusions as followed:firstly, the comprehensive development level of Wuhan has been continuously increased. The total amount of environmental pollution in Wuhan is to some degree decided by the scale of urban industrial economy, the pollution discharging efficiency of units and the output structure. Only to improve the industry and technology level, and to adjust the economic structure, can the production and emission of contaminations be appropriately reduced. Secondly, judging from the trend, the change of "three wastes" contaminations in Wuhan is not completely presented as an inverted "U" shape, along with the progress of urban development. For the stage of industrialization rapid growth, during the latest10years, the pollutions of air and solid wastes have become heavier along with the acceleration of urban development; while an inflexion similar to EKC has appeared in water pollution, but the rising trend has reoccurred due to the domestic waste water.Based on the analysis-above, two main paths of promoting urban development and environmental quality in a coordinated way have been argued in this paper:on one hand, the reasonable planning and optimized distribution should be carried out. The scale of cities should be moderate, with the compact types especially being encouraged. On the other hand, the adjustment of industrial structure, which means development limiting of polluting industries in urban regions, the innovation of regime including improving high-tech industries, and the encouragement of public participation with relevant supporting measures improvement, should be implemented, so as to actually realize the "city" to "make our lives better".