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Relating nutrient discharges from watersheds to land use and streamflow variability
Author(s) -
Jordan Thomas E.,
Correll David L.,
Weller Donald E.
Publication year - 1997
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/97wr02005
Subject(s) - base flow , environmental science , surface runoff , nitrate , streamflow , hydrology (agriculture) , nutrient , groundwater , bay , discharge , surface water , drainage basin , ecology , environmental engineering , geology , geography , oceanography , biology , cartography , geotechnical engineering
During a 1‐year period we measured discharges of water, suspended solids, and nutrients from 27 watersheds having differing proportions of cropland in the Piedmont and Coastal Plain provinces of the Chesapeake Bay drainage. Annual flow‐weighted mean concentrations of nitrate and organic N and C in stream water correlated with the relative proportions of base flow and storm flow. As the proportion of base flow increased, the concentration of nitrate increased and the concentrations of organic N and C decreased. This suggests that discharge of nitrate is promoted by groundwater flow but discharges of organic N and C are promoted by surface runoff. Concentrations of N species also increased as the proportion of cropland increased. We developed a statistical model that predicts concentrations of N species from the proportions of cropland and base flow. P concentrations did not correlate with cropland or base flow but correlated with the concentration of suspended solids, which differed among watersheds.