The Sprawl Of The American Metropolitan And The Farmland Protection (1960-2000)

In the late nineteenth century and the early twentieth century, with the continuous improvement of the level of urbanization and suburbanization in the United States, great changes have taken place in the ecological structure of America’s cities. The metropolitan with single-center structure has preliminarily formed. The metropolitan area refers to a central city with a certain size and the suburban communities which have a close relationshape with the central city. After the second world war, the population of the United States increases sharply, and the development of the city can’t meet the people’s strong demand for housing. Therefore, more and more Americans have migrated to suburbs. Meanwhile, retail, industry, commerce, office park and so on have moved into suburbs, which lead to the metropolitan spreading with a explosive trend. The size and the number of the metropolitan have been steadily increasing. In the process of metropolitan sprawling, it shows a low density characteristic. With the development of metropolitan, more and more land has been used for urban purposes, such as building houses, highways, parking lots, shopping centers, office parks, and so on, which results in the sharp decline of the land, especially the reduction of farmland with high quality. In the face of the loss of farmland, the United States sizes up the situation and explores the methods of protecting farmland actively.This paper is divided into six parts. The first part mainly introduces the farmland occupation, which results from the metropolitan sprawl. The sprawl of the metropolitan is mainly manifested in two aspects:the first one is that the size of the metropolitan is becoming bigger and bigger; the second one is that the number of the metropolitan is increasing. The reasons of the metropolitan sprawl are as follows: technical factors, American’s values, the federal government’s policies, and many other aspects. The sprawl of metropolitan has a low density characteristic, not only with a low population density, but also with a low residential density. Various land development activities have intensified the phagocytosis of farmland. Both at the national and state or local level, the farmland is declining in different degree.The second part to the fifth part are the core of this paper, which give a detail introduction to the farmland protection methods of all the levels of the governments and private organizations in the United States. In America, the state and local governments bear the main responsibilities to protect farmland, especially the local governments which play a key role in the farmland protection. Local governments use the agricultural protection zoning, purchase of agricultural conservation easements, transfer of development rights and other methods to protect the farmland; All the state governments positively explore the farmland protection methods, and gradually they create a set of a more perfect farmland protection mechanism, including regulatory protection methods, intensive-based protection methods, participatory protection methods and hybrid protection methods. At the same time, this paper takes the Oregon and California for example, presenting the farmland protection methods of the two states in detail; the federal government has enacted a variety of farmland protection bills to control of the land uses, made a detailed farmland protection planning, and provided corresponding supports to the farmland protection actions of the state and local governments. Although the federal government’s farmland protection acts have encountered several setbacks, the federal government makes a positive contribution to the farmland protection, which effectively promotes the farmland protection. In addition, the private protection organizations, especially the land trusts, take an active part in the farmland protection. Not only the national farmland trusts but also all the local agricultural land trusts have spontaneously undertaken the important task of protecting farmland.The sixth part mainly describes the meanings of the farmland protection, which has the urgency and necessity with reality. The loss of the farmland not only has caused the decrease of the agricultural production and the total value of the farm output, but also has triggered a series of social problems. Farmland protection can promote the rural employment and economic development, provide open space for human beings, protect the wildlife habitat, and keep the rural cultural heritage. Consequently, it is of great economic, ecological and social significance to protect the farmland.