The Study Of City Optimum Population Capacity Upon The Perspective Of Urban Sustainable Development

Since reformation and opening, the social economy in our country developed quickly. Urbanization accelerated. With the development of the city and the enlargement of city scale, city is formed by population's congregation and now city has become the dominate of economy. The social-economic development brings us not only the urban development but also urban problems which have inevitably blocked the further development of cities urban land-use management, urban traffic planning and management, and environmental problems are studied. It is thought that the excessive growth of urban population is the main factor contributing to all kinds of urban problems.City is the result of population's congregation. Population scale is one of the most symbol of city scale, so city master plan not only attaches great importance to the exact forecast of city population capacity, but also determines the basis of urban sustainable development.The paper firstly analyzed the relations between urban sustainable development and population capacity and it pointed out that PRED coordinated growth is the key factor of urban sustainable development. The paper then analyzed the form and change of city population, the characteristics of city population and a systemic summary was made for city population capacity. The paper analyzed forming mechanism of city scale and supply-demand equilibrium of city labor market. It pointed out that a city's demand for labor determined its population scale. The influencing factors can be described from two angles. They are social-economic factor and environment resource factor.On the basis of the optimum population theory, the paper divided urban optimum population capacity into three angles; they are economy, social and environment. Urban optimum population capacity changed with certain city development scale. At different development stages, the standards of urban optimum population capacity varied. Al last, the paper analyzed a few representative population forecast methods and pointed out that it should combine with the concrete conditions of certain cities.