Data from Selected U.S. Geological Survey National Stream Water-Quality
Monitoring Networks (WQN) on CD-ROM
Open-File Report 96-337
By Richard B. Alexander, Amy S. Ludtke, Kathleen K. Fitzgerald, and Terry L.
Schertz
Summary
Historical water-quality and streamflow data and supporting
documentation and quality-assurance information for the U.S.
Geological Survey's National Stream Quality Accounting Network
(NASQAN) and the Hydrological Benchmark Network (HBN) have
been assembled in an easy-to-use form on two CD-ROMs. The data
from these networks include measurements for a set of 63 physical,
chemical, and biological water properties for a time period spanning
the past 30 years. Network data describe stream water-quality
conditions in 679 watersheds with diverse climatic and cultural
characteristics, ranging from the relatively small, minimally
disturbed watersheds in the HBN to the larger, more culturally-
influenced drainage basins of NASQAN. Expenditures for these two
national networks have totaled approximately $95 million through
1995. Data collection has occurred during a period of significant
changes in terrestrial and atmospheric sources of water pollutants in
the United States stemming, in part, from the enactment of major
federal legislation in the 1960's and 1970's. The national networks
have provided some of the best available monitoring data for
investigating the influences of these pollutant sources on national
and regional water quality. Numerous studies have also used data
from the national networks to investigate state and local stream
water quality. Overall, national network data have been frequently
used at widely-varying geographic scales to quantify trends in water
quality, estimate rates of chemical flux from watersheds, and
investigate the relations of water quality to the natural environment
and human activities.
The CD-ROMs provide the necessary information and data-
retrieval tools to allow the national network data to be accurately
and efficiently used. In addition to the stream water-quality
monitoring data, we include ancillary information on the objectives
and characteristics of the network stations and water-quality data,
historical records of network operations and sample collection and
analytical methods, a bibliography of scientific investigations using
national network data and other publications relevant to the
networks, water reference sample data for estimating laboratory
measurement bias and variability, and discussions of statistical
methods for using reference sample data to evaluate the accuracy of
network water-quality data.
The data structure of the CD-ROMs is designed to allow users to
efficiently input the water-quality data to user-supplied software
packages including statistical analysis, modeling, or geographic
information systems. On one disc, all data are stored in ASCII form
accessible from any computer system with a CD-ROM driver. The
data can also be accessed using DOS-based retrieval software
supplied on a second disc. Logical data queries of the water-quality
data can be made for constituent concentrations, sample-collection
date, river name, station name, county state, and hydrologic unit
identifiers, and 1990 population and 1987 land-cover characteristics
for station watersheds. User-selected data can be output in a variety
of formats for subsequent use in other software packages.
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Last modified: Thu Jan 16 15:00:27 EST 1997