Global raster maps of wetland classes (33 types spanning open water, lacustrine, riverine, palustrine, ephemeral, peatland, and coastal wetlands) at ~500 m resolution, plus per-pixel wetland area. From Lehner et al. (2025), doi:10.5194/essd-17-2277-2025; see also the HydroSHEDS GLWD product page.
Both hex layers are H3 resolution 8, one row per h8 cell, hive-partitioned by
h0, with parent indexes h7/h6/h5 for multi-scale joins. Re-hexed on the
antimeridian/polar-fixed pipeline (boettiger-lab/datasets #88/#92/#93,
data-workflows #186).
glwd-hex)Z is the mode (most frequent) class per cell — query it directly, no GROUP BY
needed:
Z is categorical (0 = Dryland, 1–33 = wetland types; see classification:classes
in the STAC). Do not sum or average it.
glwd-area-hex) — answers "how many acres of wetland in ?"area_ha_x10 is the area-weighted wetland area per cell, in hectares × 10
(wetland ha = area_ha_x10 / 10). It is a complete H3 res-8 grid — area_ha_x10 = 0
where the cell has no wetland (the same full-grid shape as the carbon / ghs-pop sum
layers). An AOI join + SUM gives that AOI's wetland area directly:
SUM(area_ha_x10) is directly valid — raster-derived, one row per cell, no
per-feature duplication, no dedup. It is mass-conserving against the source COG.
The glwd-area-hex layer and glwd-cog-area COG were reconstructed by summing the
34 GLWD per-class area rasters over wetland classes 1–33 (the GLWD distribution's
single total-area COG was empty). Global total = 1,818,743,231 ha (~18.2 Mkm²),
matching the GLWD v2.0 published global wetland extent.
Lehner, B., et al. (2025). Global Lakes and Wetlands Database (GLWD) version 2.0. Earth System Science Data, 17, 2277. doi:10.5194/essd-17-2277-2025