Fraction of global land cover classes (1992 - 2022) - derived variables from ESA CCI Land Cover time series

The ESA CCI Land Cover time series describes the land surface with 22 classes at a spatial resolution of 0.002778° (~ 300 m) annually from 1992 to 2022. Here in this dataset we calculated the fraction of each class in 4 grid schemes as aggregated factors of 5, 10, 50 and 100 pixels for the whole time series. As a result, we created 22 layers per year corresponding to each of the classes for each grid scheme, representing the fraction of each class in the corresponding aggregated factors globally. We summarised the results by year, by class and by IPBES Units of Analysis (UoA). This allows end users to explore changes in the fraction of a single land cover class in their work with significantly less computational effort. Fraction of 100 pixels (A100): By land cover classes: "ESA-LCCS-1992-2022_A100_ByClass.zip" - 38 layers corresponding to 22 classes and their subclasses, each layer contains 31 years 1992 - 2022, 30 km spatial resolution, GeoTiff. By years: "ESA-LCCS-1992-2022_A100_ByYear.zip" - 31 layers corresponding to 31 years 1992 - 2022, each layer contains 38 layers corresponding to 22 class and their subclasses, 30 km spatial resolution, GeoTiff. By IPBES Units of Analysis: "ESA-LCCS-1992-2022_A100_ByUoA.zip" - 4 layers corresponding to 4 IPBES units of analysis (Urban Areas, Cultivated Areas, Forests, and Anthromes), each layer contains 31 years 1992 - 2022, 30 km spatial resolution, GeoTiff. Fraction of 50 pixels (A050): By land cover classes: "ESA-LCCS-1992-2022_A050_ByClass.zip" - 38 layers corresponding to 22 classes and their subclasses, each layer contains 31 years 1992 - 2022, 15 km spatial resolution, GeoTiff. By years: "ESA-LCCS-1992-2022_A050_ByYear.zip" - 31 layers corresponding to 31 years 1992 - 2022, each layer contains 38 layers corresponding to 22 class and their subclasses, 15 km spatial resolution, GeoTiff. By IPBES Units of Analysis: "ESA-LCCS-1992-2022_A050_ByUoA.zip" - 4 layers corresponding to 4 IPBES units of analysis (Urban Areas, Cultivated Areas, Forests, and Anthromes), each layer contains 31 years 1992 - 2022, 15 km spatial resolution, GeoTiff. Fraction of 10 pixels (A010): By land cover classes: "ESA-LCCS-1992-2022_A010_ByClass.zip" - 38 layers corresponding to 22 classes and their subclasses, each layer contains 31 years 1992 - 2022, 3 km spatial resolution, GeoTiff. By years: "ESA-LCCS-1992-2022_A010_ByYear.zip" - 31 layers corresponding to 31 years 1992 - 2022, each layer contains 38 layers corresponding to 22 class and their subclasses, 3 km spatial resolution, GeoTiff. By IPBES Units of Analysis: "ESA-LCCS-1992-2022_A010_ByUoA.zip" - 4 layers corresponding to 4 IPBES units of analysis (Urban Areas, Cultivated Areas, Forests, and Anthromes), each layer contains 31 years 1992 - 2022, 3 km spatial resolution, GeoTiff. Fraction of 5 pixels (A005): By land cover classes: "ESA-LCCS-1992-2022_A005_ByClass.zip" - 38 layers corresponding to 22 classes and their subclasses, each layer contains 31 years 1992 - 2022, 1500 m spatial resolution, GeoTiff. By years: "ESA-LCCS-1992-2022_A005_ByYear.zip" - 31 layers corresponding to 31 years 1992 - 2022, each layer contains 38 layers corresponding to 22 class and their subclasses, 1500 m spatial resolution, GeoTiff. By IPBES Units of Analysis: "ESA-LCCS-1992-2022_A005_ByUoA.zip" - 4 layers corresponding to 4 IPBES units of analysis (Urban Areas, Cultivated Areas, Forests, and Anthromes), each layer contains 31 years 1992 - 2022, 1500 m spatial resolution, GeoTiff. Data type: GriddedProjection: Plate Carrée (https://epsg.io/32662) identical to the input datasetHorizontal coverage: GlobalHorizontal resolution:1500 m (aggregated by 5; A005), 3000 m (aggregated by 10; A010), 15 km (aggregated by 50; A050), 30 km (aggregated by 100; A100)Temporal coverage: 1992 to 2022Temporal resolution: AnnualFile format: GeoTiff The IPBES Units of Analysis are the result of dividing the Earth's surface into units for the sole purpose of IPBES assessments. More information on these units can be found in Chapter 1 of the IPBES Global Assessment on Biodiversity and Ecosystem Services. Some of the IPBES units of analysis are directly derived from the ESA CCI Land Cover time series: Urban areas -> corresponds to class 190 of the land cover map, Agricultural land -> corresponds to classes 10 (including 11 and 12), 20, 30 and 40 of the land cover map, Forest areas - > corresponds to classes 50, 60 (including 61 and 62), 70 (including 71 and 72), 80 (including 81 and 82), 90, 100, 160 and 170 of the land cover map, Anthromes are also considered as the sum of urban and cultivated areas. The underlying dataset has been derived from the ESA CCI Land Cover Classification gridded maps. Version 2.0.7cds for the land cover maps for the years 1992 - 2015. Version 2.1.1 for the land cover maps for the years 2016 - 2022. This work was initially initiated within the EU Horizon ERA-Planet GEOEssential project (www.geoessential.eu). The GEOEssential project was based on an end-user-driven approach to identify environmental policy indicators and their associated Essential Variables (EVs), as well as the corresponding Earth observation data sources. As part of the GEOEssential project, we developed a workflow to aggregate the ESA CCI Land Cover Classification gridded maps into an end-user friendly format and structure. Since then we have maintained the dataset on an annual basis.欧洲航天局气候变化倡议（ESA CCI）土地覆盖时间序列以22种地物类别，以0.002778°（约300米）的空间分辨率，对1992年至2022年的地表进行逐年刻画。本数据集针对完整时间序列，以5、10、50、100像素的聚合尺度构建了4种格网方案，并计算了各类地物在各方案中的占比。最终，针对每种格网方案，我们每年生成22个图层，分别对应每一类地物，全局表征对应聚合尺度下各类地物的占比。本数据集按年份、地物类别以及IPBES分析单元（IPBES Units of Analysis, UoA）对结果进行了汇总，可使终端用户在工作中仅需极低的计算成本，即可探究单类土地覆盖类型占比的变化情况。 100像素聚合占比（A100）： 按地物类别分组：文件"ESA-LCCS-1992-2022_A100_ByClass.zip"包含38个图层，对应22类地物及其子类；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为30千米，格式为GeoTiff。 按年份分组：文件"ESA-LCCS-1992-2022_A100_ByYear.zip"包含31个图层，对应1992年至2022年的31个年份；每个图层涵盖对应年份下22类地物及其子类的共38个图层，空间分辨率为30千米，格式为GeoTiff。 按IPBES分析单元分组：文件"ESA-LCCS-1992-2022_A100_ByUoA.zip"包含4个图层，对应4类IPBES分析单元（城市区域、耕地、森林与人类足迹区）；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为30千米，格式为GeoTiff。 50像素聚合占比（A050）： 按地物类别分组：文件"ESA-LCCS-1992-2022_A050_ByClass.zip"包含38个图层，对应22类地物及其子类；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为15千米，格式为GeoTiff。 按年份分组：文件"ESA-LCCS-1992-2022_A050_ByYear.zip"包含31个图层，对应1992年至2022年的31个年份；每个图层涵盖对应年份下22类地物及其子类的共38个图层，空间分辨率为15千米，格式为GeoTiff。 按IPBES分析单元分组：文件"ESA-LCCS-1992-2022_A050_ByUoA.zip"包含4个图层，对应4类IPBES分析单元（城市区域、耕地、森林与人类足迹区）；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为15千米，格式为GeoTiff。 10像素聚合占比（A010）： 按地物类别分组：文件"ESA-LCCS-1992-2022_A010_ByClass.zip"包含38个图层，对应22类地物及其子类；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为3千米，格式为GeoTiff。 按年份分组：文件"ESA-LCCS-1992-2022_A010_ByYear.zip"包含31个图层，对应1992年至2022年的31个年份；每个图层涵盖对应年份下22类地物及其子类的共38个图层，空间分辨率为3千米，格式为GeoTiff。 按IPBES分析单元分组：文件"ESA-LCCS-1992-2022_A010_ByUoA.zip"包含4个图层，对应4类IPBES分析单元（城市区域、耕地、森林与人类足迹区）；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为3千米，格式为GeoTiff。 5像素聚合占比（A005）： 按地物类别分组：文件"ESA-LCCS-1992-2022_A005_ByClass.zip"包含38个图层，对应22类地物及其子类；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为1500米，格式为GeoTiff。 按年份分组：文件"ESA-LCCS-1992-2022_A005_ByYear.zip"包含31个图层，对应1992年至2022年的31个年份；每个图层涵盖对应年份下22类地物及其子类的共38个图层，空间分辨率为1500米，格式为GeoTiff。 按IPBES分析单元分组：文件"ESA-LCCS-1992-2022_A005_ByUoA.zip"包含4个图层，对应4类IPBES分析单元（城市区域、耕地、森林与人类足迹区）；每个图层涵盖1992年至2022年共31年的数据，空间分辨率为1500米，格式为GeoTiff。 数据类型：网格化投影为Plate Carrée（EPSG:32662，与源数据集一致）；空间覆盖范围：全球；空间分辨率：1500米（5像素聚合，即A005）、3000米（10像素聚合，即A010）、15千米（50像素聚合，即A050）、30千米（100像素聚合，即A100）；时间覆盖范围：1992年至2022年；时间分辨率：逐年；文件格式：GeoTiff。 IPBES分析单元是为开展IPBES评估而将地球表面划分为的分析单元。关于此类单元的更多信息可参考《IPBES生物多样性与生态系统服务全球评估报告》第1章。部分IPBES分析单元直接源自ESA CCI土地覆盖时间序列： 城市区域：对应土地覆盖图中的190类； 农业用地：对应土地覆盖图中的10类（含11、12子类）、20类、30类与40类； 森林区域：对应土地覆盖图中的50类、60类（含61、62子类）、70类（含71、72子类）、80类（含81、82子类）、90类、100类、160类与170类； 人类足迹区则为城市区域与农业用地的总和。 本数据集的源数据源自ESA CCI土地覆盖分类网格化地图：1992年至2015年的土地覆盖图版本为2.0.7cds，2016年至2022年的版本为2.1.1。 本数据集的研发最初始于欧盟地平线计划（EU Horizon）ERA-Planet GEOEssential项目（www.geoessential.eu）。该项目以终端用户需求为导向，识别环境政策指标及其对应的关键变量（Essential Variables, EVs）与相应的地球观测数据源。作为GEOEssential项目的一部分，我们开发了一套工作流，将ESA CCI土地覆盖分类网格化地图聚合为便于终端用户使用的格式与结构。此后，我们每年对本数据集进行维护更新。