Global Pasture Watch - Grassland reference samples based on visual interpretation of VHR imagery (2000–2022)

Reference point samples used in the production of the global maps of grassland dynamics 2000–2022 at 30 m spatial resolution in the scope of the Global Pasture Wath initiative. 

The reference samples (estabilished by Feature Space Coverage Sampling-FSCS) comprises 2.3M points visually classified (using Very High Resolution imagery) in:

1. Cultivated grassland,
2. Natural/semi-natural grassland
3. Other land cover

The file gpw_grassland_fscs.vi.vhr_tile.samples_20000101_20221231_go_epsg.4326_v1.gpkg aggregates the samples by visual interpretation units ( 1x1 km) and includes the follow collumns:

• cluster_id: Cluster id defined by k-means (FSCS),
• cluster_distance: Distance from the sample tile to center of the cluster (FSCS),
• cluster_size: Size of cluster (strata) defined by the FSCS,
• priority: Priority used by the visual interpretation,
• tile_id: Sample tile id,
• imagery: VHR reference images used by the visual interpretation,
• min_year: Minimum of year covered by the reference samples,
• max_year: Maximum of year covered by the reference samples,
• n_years: Number of years covered by the reference samples,
• n_samples_c1: Number of reference samples for "Seeded grass" (1),
• n_samples_c2: Number of reference samples for "Natural / Semi-natural grass" (2),
• n_samples_c3: Number of reference samples for "Not grass" (3),
• n_samples_all: Total number of reference samples,

The file gpw_grassland_fscs.vi.vhr_point.samples_20000101_20221231_go_epsg.4326_v1.gpkg provides individual points (with 60-m spatial support) and include the follow collumns:

• sample_id: Sample id deribed by MD5 Hash of columns x, y, imagery and year,
• x: Longitude in WGS84 (EPSG:4326),
• y: Latitude in WGS84 (EPSG:4326),
• vi_tile_id: 1-km tile id,
• imagery: VHR Reference image used by the visual interpretation (Google; Bing; Interpolated),
• ref_date: Reference date of VHR image,
• year: Reference year of VHR image,
• class: Class id (1: Cultivated grassland; 2: Natural/semi-natural grassland; 3: Other land cover) ,
• class_label: Class labels (Cultivated grassland; Natural/semi-natural grassland; Other land cover) ,
• esa_worldcover_2020: Land cover class labels extracted from ESA WorldCover 2020,
• glad_glcluc_2000: Land cover class labels extracted from UMD GLAD GLCLUC 2000,
• glad_glcluc_2005: Land cover class labels extracted from UMD GLAD GLCLUC 2005,
• glad_glcluc_2010: Land cover class labels extracted from UMD GLAD GLCLUC 2010,
• glad_glcluc_2015: Land cover class labels extracted from UMD GLAD GLCLUC 2015,
• glad_glcluc_2020: Land cover class labels extracted from UMD GLAD GLCLUC 2020,
• glc_fcs30d_2000: Land cover class labels extracted from GLC_FCS30D 2000,
• glc_fcs30d_2005: Land cover class labels extracted from GLC_FCS30D 2005,
• glc_fcs30d_2010: Land cover class labels extracted from GLC_FCS30D 2010,
• glc_fcs30d_2015: Land cover class labels extracted from GLC_FCS30D 2015,
• glc_fcs30d_2020: Land cover class labels extracted from GLC_FCS30D 2020,
• ml_cv_group: spatial block CV group (based on vi_tile_id),
• ml_type: expecify if the sample was used for (1) training or (2) calibration,

The dataset was produced through the QGIS plugin Fast Grid Inspection.