基于GIS的秦岭山区县域耕地地力调查与评价研究

Investigation and Evaluation of County-based Cultivated Land Capacity in Qinling Mountain Area Based on GIS

【目的】通过建立秦岭山区县域耕地地力评价体系,为该区土地利用的合理规划、保持生态平衡、确保耕地资源的可持续发展利用提供重要理论依据。【方法】以陕西省商洛市商南县为研究区域,选取耕地基础设施、灌溉水平、土壤结构、类型、质地、地形地貌、全氮含量、速效钾含量、有机质含量、有效磷含量、海拔高度和坡度等12个参评因子,应用ArcMap10.2软件,对商南县土地利用现状图、土壤图、行政区划图进行叠加,确定评价单元,采用层次分析、专家经验等方法计算所选因子权重,对研究区耕地地力进行评价。【结果】商南县耕地总面积24848.26 hm^2,1~5级耕地面积分别为2286.97、4666.79、8733.13、6320.22和2841.16 hm^2。其中一、二级耕地主要集中分布在河谷川塬和浅山丘陵上,三、四级耕地多分布在浅山丘陵和中山地貌上,而五级地所处的坡度较大,土壤表层质地疏松,土体厚度、腐殖质层厚度均较低。【结论】灌溉能力、地貌类型、有机质、坡度为影响商南县耕地地力评价的主要因子,改善这些因素是提高耕地生产地力主要途径。

【Objective】An evaluation system for county-based cultivated land capacity in Qinling mountain areas was established to provide important theoretical basis for the rational planning of land use,maintaining ecological balance and ensuring the sustainable development and utilization of cultivated land resources.【Method】Taking Shangnan County,Shangluo City,Shaanxi Province as the research area,12 factors including farmland infrastructure,irrigation level,soil structure,type,texture,topography,total nitrogen,available potassium,organic matter,available phosphorus,altitude and slope were selected.The current land use map,soil map and administrative map of Shangnan County were superposed to determine the evaluation unit by using ArcMap10.2 software.Analytic hierarchy process,expert experience and other methods were adopted to calculate the weight of the selected factors,and the cultivated land capacity of the study area was evaluated.【Result】The total cultivated land area of Shangnan County is 24848.26 hm^2,and the areas of cultivated land of Grade 1-5 are 2286.97,4666.79,8733.13,6320.22 and 2841.16 hm^2,respectively.The cultivated land of Grade 1 and Grade 2 are mainly distributed in river valley,tableland and hilly areas,while the cultivated land of Grade 3 and Grade 4 are mainly distributed in shallow hilly areas and middle mountains.The soil surface texture of cultivated land of Grade 5 is loose,and the thickness of soil mass and humus layer are relatively low because of the large slope.【Conclusion】Irrigation capacity,geomorphic type,organic matter and slope are the main factors affecting the evaluation of cultivated land capacity in Shangnan County,therefore,the improvement of these factors is the main way to improve the cultivated land fertility in this area.