Chemical composition and spatial variation of bulk precipitation at a coastal plain watershed in South Carolina

Journal Article · Tue Feb 01 04:00:00 EST 1983 · Water Resour. Res.; (United States)

DOI:https://doi.org/10.1029/WR019i001p00134· OSTI ID:5724696

Richter, D D; Ralston, C W; Harms, W R

Bulk precipitation was collected for analysis of ionic constituents at eight rainfall stations over a 4-year period at a 500-ha watershed in the Lower Coastal Plain of South Carolina. Mean annual deposition rates of ions in greatest supply, Cl/sup -/, SO/sub 4//sup 2 -/-S, Ca/sup 2 +/, and Na/sup +/, were respectively 14.2, 7.51, 5.69, and 5.66 kg/ha. Annual deposition rate for total inorganic N (NH/sub 4//sup +/-N plus NO/sub 3//sup -/-N) was about 2.6 kg/ha and for orthophosphate-P about 0.12 kg/ha. Spatial variation of annual depositions to the eight rainfall stations was smallest for SO/sub 4//sup 2 -/, NO/sub 3//sup -/, and Ca/sup 2 +/, with coefficients of variation (CV) less than 10%. Variation of annual inputs of the eight collectors was intermediate for Mg/sup 2 +/, Cl/sup -/, H/sup +/, and Na/sup +/ with CV ranging between 13.9 and 21.5%, whereas the CV for annual inputs of NH/sub 4//sup +/, PO/sub 4//sup 3 -/, and K/sup +/ exceeded 30%. Sample size estimates for this 500-ha watershed indicated that 19 collectors should provide estimates of the annual bulk precipitation inputs within 10% of true means for 7 of 10 ions (SO/sub 4//sup 2 -/, NO/sub 3//sup -/, Ca/sup 2 +/, Mg/sup 2 +/, Cl/sup -/, H/sup +/, and Na/sup +/) and that more than 35 collectors would be necessary to provide similar confidence intervals for annual inputs of NH/sub 4//sup +/, PO/sub 4//sup 3 -/, and K/sup +/ (+/- 10% at P < 0.05). Although estimates of annual bulk precipitation inputs may be quite variable over local areas, control of sampling errors can be gained by increasing the number of collectors.

• Research Organization: Duke Univ., Durham, NC
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5724696
• Journal Information: Water Resour. Res.; (United States), Journal Name: Water Resour. Res.; (United States) Vol. 19:1; ISSN WRERA
• Country of Publication: United States
• Language: English

Related Subjects

520200* -- Environment
Aquatic-- Chemicals Monitoring &amp; Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACID RAIN
ALKALI METALS
ALKALINE EARTH METALS
AMMONIUM COMPOUNDS
ANNUAL VARIATIONS
ATMOSPHERIC PRECIPITATIONS
CALCIUM
CHEMICAL COMPOSITION
CHLORIDES
CHLORINE COMPOUNDS
COASTAL REGIONS
DISTRIBUTION
ELEMENTS
FEDERAL REGION IV
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
MAGNESIUM
METALS
NITRATES
NITROGEN COMPOUNDS
NORTH AMERICA
OXYGEN COMPOUNDS
PH VALUE
PHOSPHATES
PHOSPHORUS COMPOUNDS
RAIN
RAIN WATER
SODIUM
SOUTH CAROLINA
SPATIAL DISTRIBUTION
SULFATES
SULFUR COMPOUNDS
USA
VARIATIONS
WATER
WATERSHEDS