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

Thesis/Dissertation · Sun Jan 01 04:00:00 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
• Country of Publication: United States
• Language: English

Related Subjects

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