基于相似推理法的土壤类型制图研究

Research on soil types mapping based on similarity inference method

关键词:  数字土壤制图  土种制图  相似推理法  第三次全国土壤普查

Key words:  Digital soil mapping  Mapping of soil species  Similarity inference method  The Third National Soil Survey

摘要:

【目的】获取准确的土壤-环境关系是保证土壤类型制图精度的关键,相似推理法是一种利用成土环境条件进行土壤类型推理的技术,对于有土属图但无土种图地区进行土种制图,本方法是一个较好的选择。【方法】本研究选取湖南省邵东市牛马司镇为研究区,参考第三次全国土壤普查的土壤类型制图方法,尝试在有二普土属图,但无土种图的地区进行耕地、园地、林地、草地土属更新制图和耕地土种推理制图的研究。以二普土属图为底图,根据土壤发生理论中不同土壤类型的理化性质以及环境因素,运用相似推理法,结合土地利用类型现状图、高空间分辨率数字正射影像和地形因子等数据更新土属图,之后结合240个耕地质量评价土壤调查样点的pH、有机质、土层厚度3个理化性质数据,完成耕地土种推理制图,并将第三次全国土壤普查表层样点的土壤类型信息更新至园林草地土属图与耕地土种图中样点所在的图斑。【结果】利用62个野外踏勘样点验证制图结果:土属图验证精度为68%,Kappa系数为0.68；耕地土种图验证精度为61%,Kappa系数为0.59。【结论】牛马司镇土壤类型推理制图结果保持了较为良好的水平,证明此方法在有土属图但无土种图地区进行耕地土种制图和非耕地更新土属图都具有可行性。

Abstract:

［Purpose］Obtaining accurate soil-environment relationship is the key to ensure the accuracy of soil type mapping, and the similarity inference method is a technique of soil type inference using soil-forming environmental conditions, which is a better choice for soil type mapping in areas with soil genera maps but without soil species maps.［Method］In this study, Niumasi Town, Shaodong City, Hunan Province, was selected as the study area, and with reference to the soil type mapping method of the Third National Soil Survey, we attempted to carry out the study of updating mapping of soil genera for arable land, garden land, forest land, grassland and mapping of soil type inference for arable land in the area where The Second National Soil Survey soil genera maps are available but soil type maps are not available. The Second National Soil Survey was used as the base map, and the soil genera map was updated according to the theory of soil genesis, using the similarity inference method, combined with the data of the land use type status map, high spatial resolution digital orthophoto map(DOM) and topographic factor, and then combined with the three physicochemical properties of pH, organic matter and soil thickness of 240 soil survey sample points for arable land quality evaluation, to complete the inference mapping of the arable land soil species, and the soil type information of surface sample points of the Third National Soil Survey was combined with the soil type information of the surface sample points of the Third National Soil Survey, and the soil type information of the soil survey sample points of the Third National Soil Survey was combined with the soil type information of the surface sample points of the Third National Soil Survey. It also updated the soil type information of the Third National Soil Survey to the soil genera and soil species maps.［Result］The results of the mapping were verified using 62 field survey sample points: the accuracy of the soil genus map was 68 per cent, with a Kappa coefficient of 0.68; the accuracy of the cultivated land species map was 61 per cent, with a Kappa coefficient of 0.59.［Conclusion］Niumasi Town soil type inference mapping results maintain a relatively good level, proving that this method has the ability to reason arable land soil species and update soil species maps in soil type inference mapping work in areas with soil genera maps but without soil species maps. map and updating soil genera map.