基于GIS的桂林市五城区耕地地力评价

为摸清桂林市五城区耕地地力现状，以指导五城区耕地资源的合理利用与改良，促进五城区农业可持续发展，利用测土配方施肥项目取得的数据，在收集整理相关图件和其它资料的基础上，在GIS支持下，将桂林市五城区土壤图和土地利用现状图叠加确定评价单元。按照农业部耕地地力评价因子选取的原则，选取立地条件、耕层理化性状及耕层养分状况等六个方面10个因子，采用模糊评价法、特尔斐法、层次分析法、累加法等对五城区耕地地力进行定量化分析和评价。评价结果表明：五城区耕地地力等级以三、四级耕地面积最大，占耕地面积的57．53％，其次是一、二级耕地，占耕地面积的27．6％，五、六级耕地面积最少，占耕地面积的14．67％，可见五城区耕地地力处于中等偏上水平。

Evaluation of the farmland productivity of five urban districts in Guilin based on GIS

In order to understand farmland productivity of five urban districts in Guilin, so as to guide resources＇ rational utilization and improvement, promote agricultural sustainable development, based on the data of soil test, relevant maps and documents, on the basis of the GIS support, the soil map and land utilization present situation of five urban districts in Guilin were overlaid to determine the evaluation unit, according to the factor selection principle of the ministry of agriculture farmland productivity assessment, ten factors in six aspects were selected such as selection of site conditions, top layer physical and chemical properties and the status of the top layer of nutrient; fuzzy evaluation method, Delphi method and analytic hierarchy process （ahp） and accumulative method were adopted with the quantitative analysis and evaluation on the farmland soil fertility. Evaluation results show that among the farmland soil fertility grades in five urban districts, three or four grade of cultivated land area occupied the largest area （57.53% of the total）, followed by the first and second grade accounting for 27.6% of the total; five and six grades accounting for 14.67% of the total arable land, which show that in general, the farmland productivity of five urban districts can reach to average and upper level.