Harvested Area and Yields of 175 Crops: Geographic Distribution of Crop Areas, Yields, Physiological Types, and Net Primary Production, 2000

This data set presents a detailed database of global land use practices describing the areas and yields of 175 individual crops circa the year 2000 at a 5 min by 5 min spatial resolution in latitude by longitude (or approximately 10 km by 10 km). The data set was created by combining national, state, and county level agricultural census statistics with a recently updated 5 min global data set of croplands. The resulting data set depicts circa the area (harvested) and yield of 175 distinct crops of the world circa 2000. Individual crop maps were aggregated to produce novel maps of 11 major crop groups, crop net primary production, and four physiologically based crop types: annuals/perennials, herbaceous/shrubs/trees, C3/C4, and leguminous/nonleguminous. The data is provided in NetCDF and ArcGIS ASCII format. The NetCDF files have 4 levels (ArcGIS files only have the 1st two levels; contact authors if you want the other two levels), as follows: Level 1 = Harvested Area (unit = proportion of grid cell area). Note that values can be greater than 1.0 because of multiple cropping. Level 2 = Yield (unit = tons per ha). Levels 3 and 4 = Administrative levels from which the source data in levels 1 and 2 come from respectively. In levels 3 and 4, a value of 1 = county; 0.75 = state; 0.5 = interpolated from within 2 degrees lat/long; 0.25 = country; 0 = missing. For more information about methods and results, please see Monfreda, C., N. Ramankutty, and J. A. Foley (2008), Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000, Global Biogeochem. Cycles, 22, GB1022, doi:10.1029/2007GB002947.

本数据集提供了一套详尽的全球土地利用实践数据库，涵盖公元2000年前后175种单一作物的种植面积与产量数据，空间分辨率为5分纬度×5分经度（约合10公里×10公里）。本数据集通过整合国家级、州级与县级农业普查统计数据，结合最新更新的5分分辨率全球农田数据集构建而成。最终生成的数据集呈现了2000年前后全球175种不同作物的收获面积与产量信息。通过对单一作物分布图进行聚合，可生成11类主要作物群、作物净初级生产力，以及四类基于生理特征的作物类型分布图：一年生/多年生植物、草本/灌木/乔木、C3/C4植物，以及豆科/非豆科植物。本数据集以NetCDF和ArcGIS ASCII格式提供。NetCDF文件包含4个数据层级（ArcGIS文件仅包含前两个层级；如需获取其余两个层级，请联系作者），具体如下：层级1为收获面积（单位：栅格单元格面积占比），需注意由于复种制度的存在，数值可能大于1.0；层级2为产量（单位：吨/公顷）；层级3与层级4分别对应层级1和层级2的源数据所来自的行政层级。在层级3和4中，数值含义如下：1代表县级，0.75代表州级，0.5代表通过2度纬度/经度范围内的数据插值得到，0.25代表国家级，0代表数据缺失。如需了解更多方法与结果细节，请参阅Monfreda C.、Ramankutty N.与Foley J. A.于2008年发表的论文《Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000》，刊载于Global Biogeochem. Cycles第22卷，文章编号GB1022，DOI:10.1029/2007GB002947。