General Information


Current Version is G3WBM ver 1.2 (updated on 17 November, 2015).
Ver1.1: river-ocean boundary is improved.
Ver1.2: bug-fix around river mouths.


Global 3 arc-second Water Body Map (G3WBM) is developed using an automated algorithm to process multi-temporal Landsat images from the Global Land Survey (GLS) database. We used 33,890 scenes from 4 GLS epochs in order to delineate a seamless water body map, without cloud and ice/snow gaps. Permanent water bodies were distinguished from temporal water-covered areas by calculating the frequency of water body existence from overlapping, multi-temporal, Landsat scenes. By analyzing the frequency of water body existence at 3 arc-second resolution, the G3WBM separates river channels and floodplains more clearly than previous studies.

If you want to download the database, please contact to the developer (Dai Yamazaki: yamadai [at] ). The JPG images of the G3WBM can be viewed without password.


Zoom up image for the Amazon Floodplain and the Ob River

Description Paper / Reference

Please use the below journal paper to cite/refer the G3WBM database.
Citation to the paper is adequate if you simply use the dataset. If you asked help for additional handling/editing of the dataset, proper acknowledgement or co-authorship is recommended.

Dai Yamazaki, Mark Trigg, and Daiki Ikeshima
- Development of a global ~90 m water body map using multi-temporal Landsat images
- Remote Sensing of Environment
- Published online, 2015, DOI: 10.1016/j.rse.2015.10.014
- Click here to access the RSE Journal Page

Poster at EGU 2015

You can download the pdf copy of our EGU 2015 poster about the G3WBM
Download the EGU2105 poster

Data Description

Data Format

The G3WBM is prepared as 5 degree x 5 degree tiles.
Filename represents the center of the lower left pixel of the data domain; e.g. the file "n30w120_wat.bil" is for the water body map of the domain N30-N35, W120-W115. (more accurately, N29.99991667-N34.99991677,W120.00004167-W115.00004167)

The 5 deg tiles are compressed into 30 degree (lat) by 60 degree (lon) package.
Package name represents the lower left corner of the package domain; e.g. the package "wat_n30w120.tar.gz" contains data files in the domain of N30-N60, W120-W060.

The data format is 'Fortran Direct Access Format' (i.e. ESRI 'BIL' raster format with the HDR file, GrADS binary with CTL file). Data is stored as 1 byte integer (little endian)



Terms and Conditions

Agreement to Terms and Conditions is required for using G3WBM.
Please e-mail to the developer to acquire password for downloading G3WBM. Please describe your name, research institute, and purpose of using G3WBM in the e-mail.

Data sharing policy

The data is freely available for research and education purpose. For commercial use, please consult with the developer (Dai Yamazaki).

Citation to the paper is adequate if you simply use the G3WBM. If you asked help for additional handling/editing of the dataset, or your research outcome highly depends on the product, the developer would request co-authorship.

90m Water Body Mask (password required)

0: Land
1: Land (No Landsat observation)
10: Snow
20: Wet Soil / Wet Vegetation / Lava
30: Salt Marsh
40: Temporal Flooded Area
50: Permanent Water
51: Permanent Water (Added by SWBD)
99: Ocean (Given by external land/sea mask)

If you need an access to previous versions, please email me.

JPEG images (password not required)

BLUE: Permanent Water Body
RED: Permanent Water Body added by SWBD
GREEN: Temporal Flooded Area
BROWN: Wet Soil/Vegetation, Lava
OCHER: Salt Marsh
YELLOW: Snow/Ice
INDIGO: Ocean Background: Topography (Slope)