农地边际化现象的宏观诊断的研究——以兰州市为例

通过对兰州市农地边际化研究总结、集成农地边际化理论，为兰州市土地利用／土地覆被变化的解释寻求出新的研究思路。在界定农地边际化的本质及其诊断标准的基础上，利用1990-2010年兰州统计年鉴、兰州市的农产品成本收益数据，对兰州市农地边际化现象进行了宏观层次的诊断研究。结果表明：近20年来，兰州市农地利用过程中出现过“1次明显的边际化现象与2次边际化迹象”。农地利用在1990-1992年出现了1次农地边际化现象的迹象；在1995-2002年，出现过最为严重，时间持续最长的1次农地边际化现象；之后的2004-2005年出现农地边际化迹象相对缓和、时间短。在农地边际化规律的作用下，集约度和播种面积都出现了明显的下降和缩小，农地边际化理论可以很好地解释兰州市近20年来农地利用中的主要变化。

Study on Marginalization of Arable Land of Macroscopic Diagnosis: A Case Study of Lanzhou

Through studying marginalization of the arable land in Lanzhou City, integrate method of marginalization of the arable land, the author sought out new research ideas for interpretation of land use/land cover change of Lanzhou City. Based on the essence and the diagnosis standard definition of the marginalization of arable land, using the data of Lanzhou statistical yearbook and the costs and returns account of agricultural products in Lanzhou from 1990 to 2010, the author diagnosed the marginalization phenomena of cultivated land use in China. The results showed that: there were once obvious marginalization phenomenon and two times suspicious marginalization evidences of the cultivated land utilization in the last two decades in Lanzhou. The first suspicious marginalization evidence of the cultivated land utilization was from 1990 to 1992. The obvious marginalization phenomenon was between 1995 and 2002, but the one was the longest and more serious. The following suspicious marginalization evidence of the cultivated land utilization from 2004 to 2005 was détente and short time. In the marginalization of the arable land under the laws, the marked decline of the degree of intensity of the cultivated land use. Theory of the marginalization of arable land use was useful to explain the changes of arable land use in China.