Global Soil Types by 0.5-Degree Grid (modified Zobler)

The Zobler digital version (Zobler, 1986) of the FAO/UNESCO Soil Map of the World (FAO, 1974) at 1 degree resolution was remapped to 0.5 degree resolution by Mac Post at Oak Ridge National Laboratory (ORNL, 1999). The resolution of the map is not actually increased. Rather, the 1 degree squares are divided into four 0.5 degree squares with the necessary fixing of continental boundaries and islands that are different. The data file is provided in ASCII format. There are 259,200 lines in the data file. Each line corresponds to a single cell in the global 720 x 360 grid. The first line of the file corresponds to the 0.5 degree cell centered on -89.75 latitude and -179.75 longitude. The first 720 values correspond to the latitude band centered on -89.75 travelling west to east. The next 720 values correspond to the latitude band centered on -89.25 and so forth. Each line contains two columns. The first column represents the continent code. The Zobler map, as distributed by Webb et al. (1992), contains a continental code. The Soil Map of the World consists of 9 maps that represent parts of the world. The texture data that Webb et al. (1996) provide allows for the fact that a soil type in one part of the world may have different properties than the same soil in a different part of the world. This continent information is therefore retained. The soil type information, also retained from the Webb et al. (1996) data, is contained in the second column of each line.

The final data file containing the 0.5 degree version of the soil map is available from ORNL by anonymous ftp at [ftp://www-eosdis.ornl.gov/data/global_soil/ZoblerSoilDerived/data]. Also available for download [ftp://www-eosdis.ornl.gov/data/global_soil/ZoblerSoilDerived/comp/] are the codes written to regrid the data, the original 1 degree data file, a land/water file used for classifying the regridded data, and a readme file explaining the regridding procedure.

1986年Zobler制作的联合国粮农组织/联合国教科文组织世界土壤图（FAO/UNESCO Soil Map of the World，FAO, 1974）数字版本，原始分辨率为1度，由橡树岭国家实验室（Oak Ridge National Laboratory, ORNL, 1999）的Mac Post重映射至0.5度分辨率。该操作并未实际提升地图分辨率，而是将1度网格单元划分为四个0.5度网格单元，并对存在差异的大陆边界与岛屿进行了必要修正。本数据集以ASCII格式存储，数据文件共包含259200行，每一行对应全球720×360网格中的单个单元格。文件首行对应以纬度-89.75、经度-179.75为中心的0.5度单元格。前720个数值对应以-89.75为中心的纬度带，自西向东排列；后续每720个数值依次对应以-89.25为中心的纬度带，以此类推。每行包含两列数据：第一列为大陆代码，Zobler地图（由Webb等人1992年发布）自带大陆编码体系。世界土壤图由覆盖全球不同区域的9幅子图组成。Webb等人1996年提供的纹理数据考虑了“同一土壤类型在全球不同区域具有不同属性”的实际情况，因此保留了该大陆编码信息。同样从Webb等人1996年的数据中保留的还有土壤类型信息，存储于每行的第二列。

最终的0.5度分辨率土壤图数据文件可通过橡树岭国家实验室的匿名FTP获取，地址为ftp://www-eosdis.ornl.gov/data/global_soil/ZoblerSoilDerived/data。此外还可下载以下资源：用于重映射该数据的代码文件、原始1度分辨率数据文件、用于对重映射后数据进行分类的陆/水掩膜文件，以及说明重映射流程的自述文件，存储地址为ftp://www-eosdis.ornl.gov/data/global_soil/ZoblerSoilDerived/comp/。