依据经济水平建立的华中-华南粮食运输模型

从中国土地利用现状出发，根据目前的中国粮食生产、粮食需求关系和地区经济水平差异等因素,建立了粮食调拨运输模型——计划经济型(非市场原理型)和市场原理型(自由购买型)。并将这两种模型分别应用到中国华中-华南地区,讨论了中国华中—华南地区的粮食储备变化特点。模拟结果显示:非市场原理型运输模型中,随着粮食运输强度系数的增大,城市地区的粮食不足现象逐步得到缓解;而粮食产地的粮食储量也将相应减少，粮食分布的区域不平衡不会长期存在。依据市场原理型运输模型,随着粮食吸收系数的增大,粮食储备迅速集中到沿海城市,此后粮食生产地区的粮食储备开始减少,内陆地区会出现大范围的粮食短缺现象。这种粮食分布的区域不平衡现象越来越大。

MODELS OF DOMESTIC CEREALS FLOW BETWEEN MIDDLE CHINA AND SOUTHERN CHINA DUE TO ECONOMIC GRADIENT

To evaluate the vulnerability of cereals transportation and cereals stock estimated from the current land use and demand supply on cereals in China, two types of numerical models (non market type and market type) were developed.The result revealed risks in decreasing cereals stock in hinterlands of productive regions and in urban regions far from productive regions, especially coastal zones in south China.In a non market type model, cereals were transported from a grid cell with positive cereals stock to a grid cell with negative cereals stock.Cereals shortage has gradually disappeared, when increasing transportation intensity co efficient in this model.Thus, excessive cereals in productive regions have also decreased and regional unbalance of cereal stocks has almost disappeared. In a market type model, each grid cell absorbed cereals from surroundings in proportion to its GDP.Some coastal urban regions showed a quick accumulation of cereals stocks, with the increasing of the cereals absorption co efficient.It appears that wide scale cereals crisis has appeared in inland regions.