Water Mask
hydrologyprocessing
Per-pixel indication of surface water presence. Canonical binary classes:
| code | class |
|------|-------|
| 0 | Non-water |
| 1 | Water |
Sources differ in temporal scope. JRC Global Surface Water (Pekel et al.
2016) summarises transition and permanence across the full Landsat record
(1984-present); ESA WorldCover and the Sentinel-2 SCL (class 6 = water)
are instantaneous scene-level products. The most common recipe is an
MNDWI or NDWI threshold over a single optical scene: MNDWI > 0 reliably
separates open water from soil and vegetation at 20 m, and Sentinel-1
backscatter thresholding extends the recipe through cloud cover. Consumed
by hydrology, flood-extent, shoreline, and water-quality ops.
Canonical units:
categorical