Surface Water Watch


G. R. Brakenridge and A. J. Kettner


Blue: Current surface water mapped by MODIS at 250 m resolution (updated daily)

Light Blue Gray: Mean Annual Flood using MODIS time series data

Dark Gray: Maximum Observed Flooding (MODIS and all other sensors, 1993 to present)

Red triangles: dams.Yellow numbers: Ramsar international wetlands


Flood Watch


G. R. Brakenridge and A. J. Kettner


Blue Mask: Mean Annual Flood

White: Presently observed flooding greater than the mean annual flood (updated daily)

Dark Gray: Maximum Observed Flooding (MODIS and all other sensors, 1993-present)

Red triangles: dams. Yellow numbers: Ramsar international wetlands


Current surface water is a rolling forward (updated daily) two week accumulation of MODIS-detected surface water. It is calculated at the Flood Observatory using information from the NASA Near Real Time Global Flood Mapping Initiative (NASA LANCE) and is at a spatial resolution of 250 m.

Mean Annual Flood is surface water detected in four out of five years by the same MODIS sensors (2012-2016). Data from the Global Surface Water Explorer at 30 m resolution (the "extent" layer) are also included. In most cases, this Landsat-based survey imaged only frequent high water.

Maximum observed flooding is a composite of water mapped by DFO since 1993 using a variety of sensors and at spatial resolutions ranging from 10 m to 250 m. There is daily MODIS water detection from the near real time flood processor since 2012. This layer is updated yearly. See also flood event pages and the DFO Web Map Server. Dam locations are from Mulligan, M. Saenz-Cruz , L., van Soesbergen, A., Smith,V.T. and Zurita,L (2009) Global dams database and geowiki. Version 1. Ramsar international wetlands are listed here.

Creative Commons License
This work, web site, and associated data are by G. R. Brakenridge and A. J. Kettner and are provided under the terms of a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Please cite the authors for non-commercial use and obtain permission prior to any commercial use. Contact or

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