Flood data rides Internet wave

As the East Coast battled record floods last month, the U.S. Geological Survey used the Internet to distribute minutes-old data about rising rivers to federal, state and local agencies responding to the emergency.

The availability of USGS' satellite-derived river data on the Internet's World Wide Web shows just how far the Net has come as a means of disseminating government data. Agencies are using the Web not only to publish data for research but also data that has a vital impact on the public health and safety.

Increasingly, this data is just a few minutes or hours old when it is put up on the Web. USGS' Water Resources Division updates its stream-flow data (http://h2o.usgs.gov/) about every four hours—but every 15 minutes during flooding conditions.

"This is exactly what the Internet is meant to be used for and what makes it so valuable," said Glee Harrah Cady, manager of information services for Netcom, a San Jose, Calif., Internet service provider.

Publishing its data on the Web is the last step in a long process for Water Resources, which has 4,200 telemetry gauges that measure the amount of water flowing through rivers nationwide. These gauges transmit measurements to a Geostationary Operational Environmental Satellite, which sends them to a USGS ground station in Tacoma, Wash., and to the National Oceanic and Atmospheric Administration's ground station on Wallops Island, Va.

From those sites, the data is sent to USGS' Automatic Data Acquisition Processing System (ADAPS) in Tacoma and then run through real-time display plotting programs. The results—called hydrographs (see bottom of photo on page 1)—are put on the Web for agencies and private citizens to access.

Others, such as the National Weather Service (NWS), bypass the Web and use the Internet to directly access the information in ADAPS. This information is not in graphical form, however.

Water Resources does not track hits on its page and state sites. But Ken Lanfear, network information products coordinator for Water Resources, said the Internet "has been very useful for people, particularly in Pennsylvania during the past flood. People were able to get the information they needed when they needed it."

This river-flow data proved critical last month, when torrential rains and warm temperatures melting heavy snows caused flooding from West Virginia to Massachusetts. One agency that depended on the USGS data was NWS, whose own computer model for predicting floods failed. The model, which is accustomed to crunching numbers using rainfall of one inch per hour, could not manage variables of snow melt and rainfall of as much as five inches an hour, NWS officials explained.

After accessing the USGS data, NWS determined that it needed to issue an evacuation notice to some residents in Harrisburg, Pa., who lived next to the raging Susquehanna River.

"Without this information, people would have lost their lives," said Frank Richards, head of the hydrolysis information center at NWS.

Water Resources has posted real-time stream-flow data on the Internet since 1994. Currently, 18 USGS state district offices, most in the Midwest and West, offer real-time stream-flow data on a Web site. All are hyperlinked to the Water Resources page, where hydrographs track stream flows over seven days.

The division is working with other state district offices to develop Web sites. The home page was improved last week when Water Resources upgraded its server and historical database to 1G, making it easier for users to locate gauging stations.

In North Bend, Wash., Robert Marion, a retired math teacher, points his browser to the USGS home page to watch the level of the Snoqualmie River, which flows 20 feet from his house. It warned him in December of an impending flood that brought 21 inches of water into his house.

"I can now pretty well determine when we need to put up the furniture," Marion said.