现代城镇化发育的土地资源基础

Land Resources and Urbanization

城市化是一个人类社会活动及生产要素从农村地区向城市地区转移的过程,其结果,城市成为了现代人类社会的生活、生产、消费和污染集聚之地。土地是城镇化发育的唯一空间载体。根据生态系统法则的演绎,城镇发育的土地资源消费或占用是通过直接、间接和诱发三种方式来实现的。更为重要的是,现代城镇发育的土地资源消费或占用是按照直接<间接<诱发的格局排列,从而构成了与自然生态系统和农村生态系统完全相佐的倒"金字塔"型结构特征。本文进一步从国家和城镇城市化两个层面证实了在这种倒"金字塔"型消费和占用结构的作用下,现代城镇发育的土地资源基础不仅在于城镇所在区域,而且也在于整个国家、乃至全球。

Urbanization is the process by which human activities and production factors shift from rural areas to urban areas. The result is that cities and towns become the locations of not only settlement and material consumption, but also other functions such as environmental pollution. Within an ecosystem, there are three types of consumption or utilization of natural resources： direct, indirect and induced. The amount of material use and environmental input for cities and towns follows the pattern of direct 〈 indirect 〈 induced. This forms an inverse pyramid structure, in contrast with the pyramid structure of a natural ecosystem. Land, as an essential resource factor, plays a key role in urbanization at a city and national scale. For an urban ecosystem, direct land-use is the city＇s actual built-up area, indirect land-use includes the area used for food production to support the city＇s residents, and induced land-use includes the areas which provide environmental services such as the provision of safe drinking water and protection of air quality. This paper uses the countr/es of China, England and the US and the cities of London, New York and Shanghai to demonstrate, using integrated input-output analysis, that the total land-use pattern for urban growth at both the national level and city level is in the structure of an inverse pyramid. This finding implies that the land-resource base necessary for the evolution of a modern city is far beyond the boundaries of the city itself.