Baltimore Ecosystem Study: Stream chemistry for Watershed 263 sites

In the Baltimore urban long-term ecological research (LTER) project,
(Baltimore Ecosystem Study, BES) we use the watershed approach to
evaluate integrated ecosystem function. The LTER research is centered
on the Gwynns Falls watershed, a 17,150 ha catchment that traverses a
gradient from the urban core of Baltimore, through older urban
residential (1900 - 1950) and suburban (1950- 1980) zones, rapidly
suburbanizing areas and a rural/suburban fringe. Our long-term
sampling network includes four longitudinal sampling sites along the
Gwynns Falls as well as several small (40 - 100 ha) watersheds located
within or near to the Gwynns Falls. The longitudinal sites provide
data on water and nutrient fluxes in the different land use zones of
the watershed (rural/suburban, rapidly suburbanizing, old suburban,
urban core) and the small watersheds provide more focused data on
specific land use areas (forest, agriculture, rural/suburban, urban).
Each of the gaging sites is continuously monitored for discharge and
is sampled weekly for chemistry. Additional chemical sampling is
carried out in a supplemental set of sites to provide a greater range
of land use. Weekly analyses includes nitrate, phosphate, total
nitrogen, total phosphorus, chloride and sulfate, turbidity, fecal
coliforms, temperature, dissolved oxygen and pH. Cations, dissolved
organic carbon and nitrogen and metals are measured on selected
samples. This dataset presents stream chemistry from the Watershed 263
subwatersheds. Watershed 263 is a 364 ha urban storm drain watershed
(or sewershed), with 30,000 residents with mixed industrial,
institutional, and residential land uses. In March 2004, we
established monitoring sites in two sub-watersheds within W263
(Baltimore Street and Lanvale Street). Both are approximately 17 ha
with 50% impervious surface and 4% vegetation cover.