Answer: The
U.S. Geological Survey (USGS) stream-gaging program provides
streamflow data for a variety of purposes that range from
current needs, such as flood forecasting, to future or
long-term needs, such as detection of changes in streamflow
due to human activities or global warming. The development
of data on the flow of the Nation's rivers mirrors the
development of the country. From the establishment of
the first stream-gaging station operated by the USGS in
1889, this program has grown to include 7,292 stations
in operation as of 1994. Data from the active stations,
as well as from discontinued stations, are stored in a
computer data base that currently holds mean daily-discharge
data for about 18,500 locations and more than 400,000
station-years of record. The stream-discharge data base
is an ever-growing resource for water-resources planning
and design, hydrologic research, and operation of water-resources
projects.
The
USGS stream-gaging program provides hydrologic information
needed to help define, use, and manage the Nation's water
resources. The program provides a continuous, well-documented,
well-archived, unbiased, and broad-based source of reliable
and consistent water data. Because of the nationally consistent,
prescribed standards by which the data are collected and
processed, the data from individual stations are commonly
used for purposes beyond the original purpose for an individual
station. Those possible uses include the following:
-
Enhancing
the public safety by providing data for forecasting
and managing floods
-
Characterizing
current water-quality conditions
-
Determining
input rates of various pollutants into lakes, reservoirs,
or estuaries
-
Computing
the loads of sediment and chemical constituents
-
Understanding
the biological effects of contamination
-
Delineating
and managing flood plains
-
Setting permit requirements for discharge of treated
wastewater
-
Designing
highway bridges and culverts
-
Setting
minimum flow requirements for meeting aquatic life
goals
-
Monitoring
compliance with minimum flow requirements
-
Developing
or operating recreation facilities
-
Scheduling
power production
-
Designing,
operating, and maintaining navigation facilities
-
Allocating
water for municipal, industrial, and irrigation uses
-
Administering
compacts or resolving conflicts on interstate rivers
-
Defining
and apportioning the water resources at our international
borders
-
Evaluating
surface- and ground-water interaction
-
Undertaking
scientific studies of long-term changes in the hydrologic
cycle
Data
for one or more of these purposes are needed at some point
in time on virtually every stream in the country, and
a data-collection system must be in place to provide the
required information. The general objective of the stream-gaging
program is to provide information on or to develop estimates
of flow characteristics at any point on any stream. Streamflow
data are needed for immediate decision making and future
planning and project design. Data, such as that needed
to issue and update flood forecasts, are referred to as
"data for current needs." Other data, such as that needed
for the design of a future, but currently unplanned, bridge
or reservoir or development of basinwide pollution control
plans, are referred to as "data for future or long-term
needs." Some data, of course, fit into both classifications;
for example, a station that supplies data for flood forecasting
and also provides data to define long-term trends.
Reference:
Wahl,
K.L., Thomas, W.O., Jr., and Hirsch, R.M., 1995The stream-gaging
program of the U.S. Geological Survey: U.S. Geological Survey
Circular 1123, 22 p. |
