Factors controlling sulfate retention and transport in a forested watershed in the Georgia Piedmont

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5672513

Shanley, J B

The mechanisms that control sulfate retention and transport were investigated at Panola Mountain, a 41-ha forested watershed in the Georgia Piedmont. The approach combined laboratory determination of soil sulfate sorption properties with a field study that was designed to infer mechanisms controlling sulfate chemistry from temporal and spatial variations in sulfate concentration and flux. Aqueous sulfate concentrations are regulated at two discrete levels: near 100 {mu}eq L{sup {minus}1} by organic-rich upper horizon soils and near 10 {mu}eq L{sup {minus}1} by deeper mineral soils. Upper horizon soils contain a large pool of labile sulfate that damps variations in sulfate concentrations. Runoff from a 3-ha granodiorite outcrop in the headwaters varied from near zero to greater than 500 {mu}eq L{sup {minus}1} sulfate. After only minimal contact with organic-rich soils, however, sulfate was regulated at 80-120 {mu}eq L{sup {minus}1} in the headwater stream. Soil solution (200 {mu}eq L{sup {minus}1} sulfate) and groundwater in the upper part of the watershed (50 {mu}eq L{sup {minus}1} sulfate) also were controlled primarily by the organic horizon. In the lower part of the basin, mineral soil regulates sulfate in groundwater and low-flow streamwater at approximately 10 {mu}eq L{sup {minus}1}. Streamwater sulfate, however, increased to 100 {mu}eq L{sup {minus}1} or more during storms. Regulation of stream sulfate concentration shifted from the sulfate-retaining mineral soil at low flow to the upper-horizon, organic-rich soil at high flow. From October 1985 to September 1988, the watershed retained 75.4% of sulfate in wet deposition. For individual storms, however, sulfate retention ranged from less than 0% (net export) to greater than 99%.

• Research Organization: Wyoming Univ., Laramie, WY (United States)
• OSTI ID: 5672513
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
GEORGIA
POLLUTION
SULFATES
ENVIRONMENTAL TRANSPORT
ECOLOGICAL CONCENTRATION
LAND POLLUTION
SOILS
WATER POLLUTION
WATERSHEDS
DEVELOPED COUNTRIES
FEDERAL REGION IV
MASS TRANSFER
NORTH AMERICA
OXYGEN COMPOUNDS
SULFUR COMPOUNDS
USA
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)