19802000北京市农业土地生产性的变动分析

根据1980、1990、2000年的统计资料和实地走访观察,本文分析了北京市乡镇一级的粮食作物、蔬菜作物和果品作物的分布格局及农业土地生产性近20年的变化。研究认为:1980年北京农业生产分布格局与土地生产性为比较典型的杜能模式;随着农业经营的多样化,1990年和2000年北京农业土地生产性呈现出多样的分布格局;北京粮食作物、蔬菜作物、果品作物的分布格局及农业土地生产性近20年的变化与此阶段的农业生产政策、农业以外的社会经济活动变化有较强的关联性;对北京以上问题的研究为验证杜能、辛克利亚、布莱昂特城市周边农业地域研究经典理论的演变提供了实证案例。

Changes of agricultural land productivity in Beijing City from 1980 to 2000

In this paper we tried to analyze agricultural land productivity changes in Beijing City from 1980 to 2000 based on statistical data and data collected from field surveys,and make clear their structure of change.For this purpose,this study explains the changes in agricultural production in Beijing City.The concrete steps are:(1) To explore the changes in agricultural production through making surveys of distributive patterns of grain crop,vegetables crop and fruits crop productivity at township level in Beijing City,and to classify various indicators and include them on maps by use GIS(ARC/INFO)to get a detailed allocation result.(2) To define the regional change patterns of agricultural land productivity at township level in Beijing City.The results of the survey lead to the following conclusions. First,agricultural crop production has changed as the policies influencing the agricultural production has changed.Second,in graphical terms,the agricultural land productivity map took a circular pattern centered on the city proper in 1980,and this was confirmed by Thünen's model.This round shape structure could not be seen in 1990 and 2000.Although this did not match Thünen's or Sinclar's models in 1990,it was a fact that agricultural production had become more flexible.In 2000,the agricultural land productivity was still high in places close to the city proper,the area of these townships became minor because of the expansion of urban regions.Many higher productivity townships were gathered in the northeast of the city.In this respect,Bryant's model could be seen.In general,the agricultural land productivity of Beijing City was influenced either by natural conditions or the changes in governmental policies.Third,The changes in agricultural production among rural areas are diversified in Beijing City.The reason for the diversification is doubtless that,because of varying natural conditions,different agricultural production policies have been applied to each agricultural region,leading to differences in crop production.