关键词: 人口, 粮食, 土地资源承载力, 土地资源承载指数, 中国

Abstract: With the increase of population, land carrying capacity and food safety have been attracted great attention worldwide. From the point of man-grain relationship, based on GIS techniques,by setting up the land carrying capacity(LCC) and the land carrying capacity index(LCCI) models, this paper firstly analyzes the spatial-temporal dynamic patterns of land carrying capacity of China between 1949 and 2005 at county, province and country level. Choosing 2005 as the typical year, this paper then evaluates the land carrying capacity of 264 pastoral(semi-pastoral)regions, 663 urban regions and 592 poverty-stricken regions of China. The result shows that: (1) From 1949 to 2005, with the increase of grain production, the land carrying capacity of China has been improved conspicuously, but for the rapid population growth, it still only balances with the low level grain consumption. (2) Over the last 25 years (1980-2005), the number of overloading provinces decreased from 23 to 15 and the man-grain relationship was bettered gradually, but there were more overloading provinces than surplus provinces in China. (3) At county level, there were 1572 overloading counties in 1980 whic accounted for 68.26% of the total with a population of 649 million, while in 1990,2000 and 2005, the number of overloading counties was 1066, 1133 and 1087 respectively,indicating that the man-grain relationship has been improved obviously during the past 25 years; as for spatial distribution, the surplus counties are mainly concentrated in agriculture developed regions, such as Northeast Plain, North China Plain, Middle and Lower Reaches of the Yangtze River Plain etc., and overloading counties are mainly located in regions with poor natural environment and low grain production capacity, such as Northwest China, Tibetan Plateau and Loess Plateau etc. and economy developed urban regions, such as Beijing, Tianjin and Shanghai etc. (4) Grassland husbandry led to great improvement of the land carrying capacity of pastoral and semi-pastoral regions, while urban regions were overloaded due to population concentration and more than half of the poverty-stricken regions were overloaded with critical natural environment and poor economic condition.

Key words: population, grain, land carrying capacity, land carrying capacity index, China