Watershed nitrogen and phosphorus balance: The upper Potomac River basin
Nitrogen and phosphorus mass balances were estimated for the portion of the Potomac River basin watershed located above Washington, D.C. The total nitrogen (N) balance included seven input source terms, six sinks, and one 'change-in-storage' term, but was simplified to five input terms and three output terms. The phosphorus (P) baance had four input and three output terms. The estimated balances are based on watershed data from seven information sources. Major sources of nitrogen are animal waste and atmospheric deposition. The major sources of phosphorus are animal waste and fertilizer. The major sink for nitrogen is combined denitrification, volatilization, and change-in-storage. The major sink for phosphorus is change-in-storage. River exports of N and P were 17% and 8%, respectively, of the total N and P inputs. Over 60% of the N and P were volatilized or stored. The major input and output terms on the budget are estimated from direct measurements, but the change-in-storage term is calculated by difference. The factors regulating retention and storage processes are discussed and research needs are identified.
- Research Organization:
- Environmental Protection Agency, Narragansett, RI (United States). Environmental Research Lab.
- OSTI ID:
- 6192665
- Report Number(s):
- PB-93-199586/XAB; EPA-600/J-93/199
- Resource Relation:
- Other Information: Pub. in Estuaries, Vol. 15, No. 1, 83-95(Mar 1992)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NITROGEN
BALANCES
PHOSPHORUS
POTOMAC RIVER BASIN
WATER POLLUTION
ACID RAIN
AGRICULTURAL WASTES
AIR-WATER INTERACTIONS
ATMOSPHERIC CIRCULATION
BUDGETS
DENITRIFICATION
DEPOSITION
EXPORTS
INFORMATION NEEDS
INPUT-OUTPUT ANALYSIS
LOADING
MASS BALANCE
NUTRIENTS
POINT SOURCES
RESEARCH PROGRAMS
RETENTION
RIVERS
SINKS
SOURCE TERMS
STORAGE
WASHINGTON
WATERSHEDS
ATMOSPHERIC PRECIPITATIONS
CHEMICAL REACTIONS
DEVELOPED COUNTRIES
ECONOMIC ANALYSIS
ECONOMICS
ELEMENTS
MATERIALS HANDLING
MEASURING INSTRUMENTS
NONMETALS
NORTH AMERICA
ORGANIC WASTES
POLLUTION
RADIATION SOURCES
RAIN
STREAMS
SURFACE WATERS
TRADE
USA
WASTES
WEIGHT INDICATORS
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)
540320 - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)