基于GIS的江苏省溧阳市耕地地力评价研究

以江苏省溧阳市为研究区域，以耕地地力评价为研究对象，以县域耕地资源管理信息系统软件为应用平台，用GIS技术将各种属性数据和空间数据进行处理与整合；采用土地利用现状图和土壤图叠加形成评价单元；结合耕地的自然要素选择12个因素作为评价因子；采用相关分析、因子分析、模糊评价、层次分析等数学分析原理，构造层次结构、建立评价因子隶属函数模型及计算各因子的权重，建立了一种定性与定量相结合的耕地地力评价方法。采用累积曲线法来确定耕地地力等级数目以及划分等级界限，将全市56251hm^2耕地，划分为5个等级。其中一级地1309hm^2，占2．30％；二级地20689hm^2，占36．78％；三级地31097hm^2，占55．28％；四级地3136hm^2，占5．60％；五级地20hm^2，占0．04％。研究结果表明，地力等级的划分和各等级的比重确定比较科学和客观，评价结果较准确地反映了研究区域内耕地地力的状况，基本符合当地的客观实际，表明所采用的评价方法对耕地地力评价具有可行性和科学性，对科学管理耕地具有指导意义。

A GIS-based Research of Evaluation on Cultivated Land Productivity in Liyang City, Jiangsu Province

Abstract： The studied area in this paper was Liyang City, Jiangsu Province, China, and the research object was the evaluation for cultivated land productivity. Management information system software at county level was used as application platform. GIS technology was used for dealing and combining all kinds of property data and spatial data. Evaluation unit was formed by combining land present usage images with soil images. By considering the nature essential factors of cultivated land, 12 factors were chosen as evaluation factors. By using the mathematical analysis theories such as correlation analysis, factor analysis, fuzzy evaluation, AHP （analytic hierarchy process） and so on, hierarchical structure was constructed, and the evaluation factors were set up which belonged to the models of membership function and calculated the weighting of each factor. A method of evaluation on the cultivated land productivity which combined qualitative analysis with quantitative analysis, had been established. The number and limit of cultivated land productivity level was determined by using the method of cumulative frequencies curve. The total area of cultivated land in Liyang City was 56251 hectares, which was divided into five levels, i.e., the 1st level with 1309 hm^2 accounting for 2.30% of the total cultivated land area, the 2nd with 20689 hm^2 for 36.78%, the 3rd with 31097 hm^2 for 55.28%, the 4th with 3136 hm^2 for 5.60%, and the 5th with 20 hm^2 for 0.04%. The research results showed that the divisions of cultivated land productivity levels and proportion of each level were scientific and objective, could reflected the status of cultivated land productivity correctly in the studied area, and was basically in line with local objectivity. Hence, the research method has feasibility and scientificalness for the evaluation on the euhivated land productivity.