DOI: 10.5281/zenodo.11279264
title: Global Pasture Watch - Grassland reference samples based on visual interpretation of VHR imagery and harmonized datasets (2000–2024)

description: Reference point samples used in the production of the global maps of annual grassland class and extent for 2000—2022 within 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:



Cultivated grassland,

Natural/semi-natural grassland

Other land cover


The file gpw_grassland_fscs.vi.vhr_tile.samples_20000101_20241231_go_epsg.4326_v2.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 "Cultivated grass" (1),

n_samples_c2: Number of reference samples for "Natural / Semi-natural grass" (2),

n_samples_c3: Number of reference samples for "Open Shrubland" (2),

n_samples_c4: 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_20241231_go_epsg.4326_v2.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,

tile_id: GLAD tile id (1x1 degree)

imagery: VHR Reference image used by the visual interpretation (Google; Bing; Interpolated),

ref_date: Reference date of GPW samples (based on VHR image) and of other existing datasets,

year: Reference year of GPW samples (based on VHR image) and of other existing datasets,

class: Class id (1: Cultivated grassland; 2: Natural/semi-natural grassland; 3: Open shrubland; 4: Other land cover) ,

class_label: Class labels (Cultivated grassland; Natural/semi-natural grassland; Open shrubland; Other land cover) ,

dataset_name: Existing dataset names (CGLS-LC, EuroCrops, GeoWiki, GeoWiki-feedback, LCMap-Conus, LUCAS, MapBiomas, WorldCereal, GPW) dataset_class:  Original land cover class provided by the maintainer of existing dataset

esa_worldcover_2020: Land cover class labels extracted from ESA WorldCover 2020,

glad_glcluc_yyyy: Land cover class labels extracted from UMD GLAD GLCLUC for the reference date,

glc_fcs30d_yyyy: Land cover class labels extracted from GLC_FCS30D for the reference date,

gpw_fscs_cluster: K-Means output ranging from 0—9999 according to Feature Space Coverage Sampling (FSCS),

ml_cv_group: spatial block CV group (based on vi_tile_id),

ml_type: specify if the sample was used for (1) training or (2) calibration.


The file gpw_grassland_fscs.vi.vhr_grid.samples_20000101_20241231_go_epsg.4326_v2.gpkg provides the grid samples (with 10-m spatial support) and include the follow collumns:



tile_id: 1-km tile id,

bing_class: Class labels (Cultivated grassland; Natural/semi-natural grassland; Other land cover) defined using as reference Bing Maps Images,

bing_image_start_date: Start date of the Bing Maps Images used in the visual interpretation,

bing_image_end_date: End date of the Bing Maps Images used in the visual interpretation,

google_class: Class labels (Cultivated grassland; Natural/semi-natural grassland; Other land cover) defined using as reference Google Maps Images,

google_image_start_date: Start date of the Google Maps Images used in the visual interpretation,

google_image_end_date: End date of the Google Maps Images used in the visual interpretation,

missing_image_date: No images available,

same_image_bing_google: Images from the same date available in Google and Bing Maps.


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

Related resources



Maps of dominant grassland:2000-2002 2003-2005 2006-2008 2009-2011 2012-2014 2015-2017 2018-2020 2021-2022

Probability maps of cultivated grassland:2000-2022 (All URLs)

Probability maps of natural/semi-natural grassland:2000-2022 (All URLs)

Grassland reference samples based on VHR imagery (2000–2022):GeoPackage files

Global machine learning models (Random Forest):Parquet and joblib python files

Reference sampling design derived by FSCV:GeoPackage and raster files

Harmonized reference samples based on existing LULC dataset:GeoPackage and raster files

Source code for reproducibility:GitHub release

Mapping feedback tool:GeoWiki

Data catalogues:OpenLandMap STAC Google Earth Engine


Support

For questions of bugs/inconsistencies related to the dataset raise a GitHub issue in https://github.com/wri/global-pasture-watch