US Geological Survey launches tool for stream-flow prediction

Currently consisting of a pilot scheme covering the state of Massachusetts, the USGS plans to implement the service throughout the country as part of its National Streamflow Information Programme. The scheme offers users flow-duration statistics, August median flows, flood-flow frequency statistics, and low-flow frequency statistics, which includes a low flows for a variety of recurrence intervals.

“With this new web-based tool, users can view maps of areas of interest.

They need only to select a site on a stream to get estimates of stream-flow

statistics”, said Kernell Ries, USGS hydrologist, and principal

researcher. “Automatically the physical characteristics of the watershed

that drains to the site will be measured, a set of equations will be

solved, and the estimated stream-flow statistics and a location map will be provided to your desktop within seconds.”

Though downloading the information can be slow in internet terms, particularly for the detailed maps, it is considerably faster than previous data gathering and analytical techniques which could take days, says the USGS. The programme is relatively complicated, but the website provides a comprehensive tutorial, and, says the USGS, the system does not require any advance experience in hydrology, computer science or geographic analysis.

“The Streamstats program is an essential tool for state planning and permitting agencies,” said Vicki Gartland, a water-resources programme manager at the Massachusetts Department of Environmental Management. “Streamstats quickly provides important stream-flow statistics used for managing stressed river basins and calculating potential impacts of water withdrawals in areas without gages. Also, Streamstats allows us to determine how much industrial waste a given river or stream can handle. That’s important when it comes to issuing permits.” According to the USGS, the scheme could also be used for determining the stream-flow needs of aquatic plants and animals, designing structures such as bridges, culverts, spillways or floodwalls, land-use planning and

developing flood insurance rate maps.

The system works through a set of 13 equations that can be used to estimate stream-flow statistics based on long-term records of flow from USGS stream gages. At present, the website only provides low-flow statistics, but work is also underway to incorporate flood statistics.