基于GIS的耕地定级方法及其应用

根据模糊数学和多元统计分析原理，建立了一个定量的耕地定级方法，并以湖北省鄂州市进行了实例说明，从而为该地区耕地的合理利用与管理提供依据,有利于实现耕地资源的信息共享和城乡土地市场一体化的建立。首先采用灰色关联分析法筛选定级因子，层次分析法确定相应的权系数；矢量化相关图层并提取农贸中心和道路作缓冲区分析后，采用多边形法确定耕地评价单元；通过采用不同的分值函数对因子属性值进行标准化；最后采用综合指数模型计算定级指数并根据聚类分析法将鄂州市耕地划分为5级，利用ArcGIS实现定级结果图的输出。定级结果表明：鄂州市耕地质量中等偏上，以二、三级地为主，共占74.78 %，该评价结果基本符合实际，同时利用GIS引入缓冲区分析方法来获取部分评价因子数据，提高了评价结果的准确性。

GRDATION OF CULTIVATED LAND IN EZHOU CITY ON THE BASIS OF GIS

An evaluation method for the gradation of cultivated land was developed on the basis of GIS, and fuzzy mathematics, and was then used for analyzing the gradation of cultivated land in Ezhou city in order to promote rational utilization and scientific management of arable land resources and also to set up an information system for arable land and for land market of urban and rural area. Factors and weight of affecting arable land quality were decided by grey analysis and AHP. ArcGIS was also used to obtain gradation unit, with layers analysis on buffer areas of trade centers and road overlaid by layers of other factors affecting cultivated land quality. The value of factors was standardized by different value functions, and indexes of gradation were calculated by the synthetic index method. Finally, cultivated land level was divided according to analytical clustering process (ACP). With ArcGIS, an evaluation map drawn on the gradation of cultivated land in Ezhou city. It is revealed that the quality in this area ranged from medium to high, and the areas in levels 2 and 3 accounted for 71.98%, which is in accordance with the local situation. By using buffer area analysis, reliable data of evaluation factors could be obtained with improved accuracy. It is proposed that the method used in the present study may also provide reference for other studies on land gradation.