关键词: 环境质量, 纬度地带性, 经济重心, 自然资源, 域迁移, 源结构, 经度地带, 自然环境, 运动形态, 矿产资源

Abstract: Economic centres shift constantly owing to various factors. The United States is entering the Post-industrial period and its economic centres are shifting towards the south, [n China, the southward shifting of the economic centres may take place even before the country enters the Post-industrial period as the northern part of China is in serious lack of water, whereas the southern part of the country ooasts of a host of fine ports.The location of natural resources is one of the reasons that account for the southward shifting of the economic centres. Natural resources form an indispensable conditions of economic development of the society. Although nature is the external cause of social development, but it is as important a factor as the internal cause. Under certain circumstances, it can become the decisive factor in the shifting of the economic centres.There are three types of natural resources whose location has a fairly great impact on the shifting of the economic centres. These three types are as follows:1) Means of production (e.g. fertile soil), which have an attraction for the agricultural society;2) Means of labour (e.g. minerals), which have an attraction for the industrial society; and3) Good environment, which has an attraction for the Post-indutrial society.The location of the natural resources causes the shifting of economic centres between-south and north, east and west.