MOD44W v061

MODIS/Terra Land Water Mask Derived from MODIS and SRTM L3 Yearly Global 250 m SIN Grid

PI: Mark Carroll


The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) Land Water Mask (MOD44W) Version 6.1 data product provides a global map of surface water at 250 meter (m) spatial resolution. The data are available annually from 2000 to present. MOD44W Version 6.1 is derived using a decision tree classifier trained with MODIS data and validated with the Version 5 MOD44W data product. A series of masks are applied to address known issues caused by terrain shadow, burn scars, cloudiness, or ice cover in oceans. Version 6.1 is the generation of a time series rather than a simple static representation of water, given that water bodies fluctuate in size and location over time due to both natural and anthropogenic causes. Provided in each MOD44W Version 6.1 Hierarchical Data Format 4 (HDF4) file are layers for land water mask and water body classification. A quality assurance (QA) layer provides users with information on the determination of water. The new seven class water classification layer provides values for shallow ocean, land, shoreline, inland water, ephemeral water, deep inland water, moderate ocean, deep ocean, and a classification deemed to fall outside of the projection.

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Improvements/Changes from Previous Versions

  • Additional data files will be produced annually and are scheduled for distribution in the first quarter of the calendar year.
  • Seven-class water body classification layer produced at 250 meter resolution is provided in tiled format.
  • For Collection 6.1 and beyond, Antarctica data are now being produced.

Collection and Granule


Characteristic Description
CollectionTerra MODIS
File Size~2.5 MB
Temporal ResolutionYearly
Temporal Extent2000-01-01 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
File FormatHDF-EOS
Geographic Dimensions1200 km x 1200 km


Characteristic Description
Number of Science Dataset (SDS) Layers3
Columns/Rows4800 x 4800
Pixel Size250 m

Layers / Variables

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Water_mask Land/Water Mask N/A 8-bit unsigned integer 250 253 0 to 1 N/A
Seven_class Water Body Classification Layer N/A 8-bit unsigned integer 250 253 0 to 7 N/A
Water_mask_QA Quality Assurance (QA) N/A 8-bit unsigned integer 10 253 1 to 9 N/A

Water Mask Values

Class Description
0 Land
1 Water
250 Outside of Projection

Water Body Classification Values

Class Description
0 Shallow ocean
1 Land
2 Shoreline
3 Inland water
4 Ephemeral water
5 Deep Inland water
6 Moderate ocean
7 Deep ocean
250 Outside of Projection

Quality Assurance Index

Class Description
1 High Confidence Observation
2 Low Confidence Water
3 Low Confidence Land
4 Ocean Mask
5 Ocean Mask but no water detected
6 Burned Scar (from MCD64A1)
7 Urban/impervious Surface
8 No water detected, Collection 5 shows water
9 Model predicted water, DEM slope indicates no water
10 Fill (outside of projected area)

Product Quality

Quality information is provided in the Water Mask QA layer. Additional product quality information is provided in the product quality description section of the User Guide and Algorithm Theoretical Basis Document (ATBD).

Known Issues

The seven_class SDS layer legend for classes 4 and 5 are incorrectly listed as Deep Inland Water and Ephemeral Water in the data for the entire mission period. Users are requested to follow the legend provided in the User Guide or the Water Body Classification Values table above.

About the image

Terra MODIS Annual Water Mask data from MOD44W v6.1 over Lake Superior and surrounding areas for 2022.

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User Guide and Algorithm Theoretical Basis Document (ATBD)

Using the Data

Access Data


DOI: 10.5067/MODIS/MOD44W.061