European Soil Database (ESDB) - version 2.0, Sep. 2001

The Soil Geographical Database of Eurasia at Scale 1:1,000,000 is part of the European Soil Informaton System (EUSIS). It is the resulting product of a collaborative project involving all the European Union and neighbouring countries. It is a simplified representation of the diversity and spatial variability of the soil coverage. The methodology used to differentiate and name the main soil types is based on the terminology of the F.A.O. legend for the Soil Map of the World at Scale 1:5,000,000. This terminology has been refined and adapted to take account of the specificities of the landscapes in Europa. It is itself founded on the distinction of the main pedogenetic processes leading to soil differentiation: brunification, lessivage, podzolisation, hydromorphy, etc. The database contains a list of Soil Typological Units (STU). Besides the soil names they represent, these units are described by variables (attributes) specifying the nature and properties of the soils: for example the texture, the water regime, the stoniness, etc. The geographical representation was chosen at a scale corresponding to the 1:1,000,000. At this scale, it is not feasible to delineate the STUs. Therefore they are grouped into Soil Mapping Units (SMU) to form soil associations and to illustrate the functioning of pedological systems within the landscapes. Harmonisation of the soil data from the member countries is based on a dictionary giving the definition for each occurrence of the variables. Considering the scale, the precision of the variables is weak. Furthermore these variables were estimated over large areas by expert judgement rather than measured on local soil samples. This expertise results from synthesis and generalisation tasks of national or regional maps published at more detailed scales, for example 1:50,000 or 1:25,000 scales. Delineation of the Soil Mapping Units is also the result of expertise and experience. Heterogeneity can be considerable in European regions. The spatial variability of soils is very important and is difficult to express at global levels of precision. Quality indices of the information (purity and confidence level) are included with the data in order to guide usage. This metadata record is adapted from the orginal one received from JRC.《1:100万比例尺欧亚大陆土壤地理数据库》隶属于欧洲土壤信息系统（European Soil Information System, EUSIS）。该数据库是欧盟及其所有周边国家联合协作项目的最终成果，旨在简化呈现土壤覆盖的多样性与空间变异特征。其用于区分并命名主要土壤类型的方法，基于联合国粮食及农业组织（F.A.O.）1:500万世界土壤图的图例术语体系，并针对欧洲区域景观的特异性进行了优化与适配。该方法体系的核心依据是对主导成土过程的区分，包括褐土化作用、粘化淋溶作用、灰化作用、水成作用等。 该数据库包含土壤类型单元（Soil Typological Units, STU）列表。除其所代表的土壤名称外，这些单元还通过多项变量（属性）进行描述，用以说明土壤的本质与特性，例如土壤质地、水分状况、石砾含量等。本次数据库采用1:100万比例尺进行空间表达，但在此比例尺下无法单独勾绘土壤类型单元，因此将其归并为土壤制图单元（Soil Mapping Units, SMU），以形成土壤组合，并展现景观内土壤系统的运作规律。 针对各成员国土壤数据的协调统一工作，依托一份为各变量条目提供明确定义的词典完成。受该比例尺限制，相关变量的精度相对有限；且此类变量多通过专家研判对大范围区域进行估算，而非基于原位土壤样品开展实测。此类专家研判成果源自对更详细比例尺（如1:5万或1:2.5万）发布的国家或区域土壤图进行综合与概化处理的工作。土壤制图单元的勾绘同样依托专家经验与专业研判完成。欧洲区域的土壤异质性可能十分显著，土壤空间变异程度极高，难以在全球精度层级下实现精准表达。数据库同步附带信息质量指标（包括纯度与置信水平），以辅助用户合理使用数据。 本元数据记录改编自欧盟联合研究中心（Joint Research Centre, JRC）提供的原始元数据。