River Watch Version 3.4
Satellite River Discharge Measurements (clickable dots)

Technical Summary

Resumen Técnico

Technical Report and Data Product Specifications, Global Flood Detection System

Updated Daily at 14:30 Local Denver Time

White triangles: ice covered. Yellow dots: low flow (<20th percentile discharge for this day of the year, 2003-2013; Blue dots: normal flow; Purple dots: moderate flooding (>1.5 yr recurrence interval); Red, major flooding (> 5 yr recurrence interval).

Period of record for non-high latitude sites begins January 1, 1998. The Log-Pearson III distribution is used for recurrence interval calculation.

Accessing the discharge and runoff data: The daily discharge and runoff data are provided in html format for each site (click "obtain data" link shown on each site display).

To obtain the source microwave signal data, use the following two links:

These remote sensing data are provided in separate columns as SignalAvg (ratio) values, and MagnitudeAvg values (standard deviation units away from the site mean). The River Watch processor uses the SignalAvg values. In some cases (> ~ 45 deg latitude N and S), data extend back to only June, 2002 instead of 1998, and there is a data gap between October 6, 2011 and September 13, 2013. A tabular listing of all sites is available also.

Brief Explanation: Flow area within a 10 km river reach (a "satellite gauging site") is a direct indicator of discharge. The River Watch Version 3.4 processor and associated algorithms use microwave radiometry, from existing and previous satellites, to monitor flow area changes along an expanding suite of gauging sites. Data are updated daily, and, below 50 degrees latitude, extend continuously back to 1998. At higher latitudes, data extend only to mid-2002. A global hydrologic model, run for five years (2003-2007) with daily time steps (WBM) is used to calibrate the flow areas to discharge information. Technical summaries in Spanish and English (links provided above) and a manuscript in press provide explanation of the indicators used to assess site accuracy and also information about the ice cover detection algorithm.

Earlier version sites still online will soon be updated to the new version.

Predicted Flooded Area: Each River Watch site will eventually be linked to a "Predicted Flooded Area" display; the links are installed already. See a manuscript, in press.

Citing these data or displays: Brakenridge, G.R., De Groeve, T., Kettner, A., Cohen, S., and Nghiem, S. V., date of display, River Watch, University of Colorado, Boulder, CO, USA (http://floodobservatory.colorado.edu/DischargeAccess.html). Or include individual site display numbers and location (e.g., http://floodobservatory.colorado.edu/SiteDisplays/446.htm).

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