MOD44W v006

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

Description

The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) Land Water Mask (MOD44W) Version 6 data product provides a global map of surface water at 250 meter (m) spatial resolution. The data are available annually from 2000 to 2015. MOD44W Version 6 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. A primary improvement in Version 6 is the generation of time series data 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 Hierarchical Data Format 4 (HDF4) file are layers for land, water, no data, and an associated per pixel quality assurance (QA) layer that provides users with information on the determination of water.

Characteristics

Improvements/Changes from Previous Versions

  • Corrected for errors of many misplaced rivers in South America due to limited spatial resolution of previously used input data.
  • Improved data in the far northern latitudes.
  • Water extent provided as a time series that can be used to detect changes between 2000 and 2015.
  • Increased spatial resolution of 250 m. The Version 5 product was 500 m.
  • Improved terrain shadows with slope and elevation masking.
  • Burned areas (scars) delineated.

Collection and Granule

Collection

Characteristic Description
CollectionTerra MODIS
DOI10.5067/MODIS/MOD44W.006
File Size~500 KB
Temporal ResolutionYearly
Temporal Extent2000-01-01 to 2015-12-31
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS
Geographic Dimensions1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers2
Columns/Rows
Pixel Size250 m

Layers

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
Water_mask_QA Quality Assurance (QA) N/A 8-bit unsigned integer 10 253 1 to 8 N/A

Water Mask Values

Class Description
0 Land
1 Water
250 Outside of Projection

Quality Assurance Index

Class Description
1 High confidence observation
2 Lower confidence water, but MOD44W V5 indicated water
3 Lower confidence land
4 Ocean mask
5 Ocean mask, but no water observations recorded
6 Burned area (MCD64A1)
7 Urban or impervious surface
8 No water detected, but MOD44W V5 shows inland 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 on page 5 of the User Guide and Algorithm Theoretical Basis Document (ATBD).

Known Issues

Known issues are described in the User Guide and ATBD.

Documentation

Using the Data

Tools

Citation

DOI: 10.5067/MODIS/MOD44W.006

About the Image