The Hydrologic Benchmark Network (HBN) was established in 1963 to provide
long-term measurements of streamflow and water quality in areas that are minimally affected
by human activities. These data were used to study long-term trends in surface water flow
and water chemistry and as a benchmark against which to compare changes in flow and chemistry
in developed watersheds. At its peak the network consisted of 58 drainage basins in 39 States.
Over time, changes in funding and land use within the watersheds reduced the number of stations
and samples collected by HBN. In the mid-1990s, the USGS conducted a complete review of the
network, and selected 5 eastern stations to conduct a pilot study to assess the optimum sampling
strategy for assessing long-and short-term trends. |
|