关键词: 青藏高原, 粮食生产, 粮食消费, 粮食安全, 空间格局

Abstract:

The problem of grain shortages has long plagued the Tibetan Plateau, therefore both the state and the local government are scaling up efforts to achieve grain self-sufficiency and grain security in this region. Meanwhile, many researchers devoted themselves to study the grain security issues to provide rational advices. Here in this paper, we intended to analyze the temporal and spatial characteristics of grain production and consumption in the Tibetan Plateau and then evaluate the risk status of grain security in 114 counties. First, we revised the standards of per capita grain consumption demand in pasturing area and farming-pastoral region. Then, on this basis, we analyzed the corresponding data of the 114 counties during 1985-2015 by applying the fluctuation coefficient method, classification method, barycenter model and the index model of grain shortages. Analytical results showed that there was a non-uniform geographical distribution of grain production and consumption, moreover, the holistic status of grain security in the Tibetan Plateau was not optimistic. (1) The production of grain increased in fluctuation and the consumption of grain grew steadily, the local grain production could not meet the consumption demand, and the deficit amounts were between 0.21 and 1.22 million tons annually, which accounted for between 8.22% and 40.11% of the grain consumption. The gap between grain production and consumption including tourists increased to 1.33 million tons in 2015. (2) The spatial distributions of grain production and grain consumption in the Tibetan Plateau were imbalanced, the grain yields in Huang-Huang valley and the valley along the?Yarlung?Zangbo?River were higher, while the yields distributed in the central and western parts of the plateau were lower. Affected by population, city, and traffic distribution, the grain consumption was high in the eastern part and low in the western. (3) The spatial patterns of grain security in the Tibetan Plateau in 2015 showed that the higher-risk types involved 42 counties with a population of 2.92 million, and they were widely distributed in western Tibet, northern Tibet, southern Qinghai, Qilian Mountains, as well as in municipal districts of cities of Lhasa and Xining; compared to 1985, the risks of grain security on the midstream and downstream of Yarlung Zangbo River and southeastern Qinghai province were mitigated, while those in western Ngari and northeastern Qinghai were intensified. (4) The tourists increased the risks of grain security in Lhasa, Nyingchi, Shannan, Shigatse, Haidong and Hainan cities, and the negative influence of tourist on Linzhi city was most significant. (5) Production increase alone cannot solve the problem of grain shortage, so it is urgent for the Tibetan Plateau to improve the grain reserves, transportation facilities and expand the grain trade with other regions to achieve regional grain security.

Key words: Tibetan Plateau, grain production, grain consumption, grain security, spatial pattern