ABSTRACT:
Sediment deposition from 1880 to 1979 was estimated for the riparian zone of a coastal plain agricultural watershed. Two approaches were used: (1) deposition estimates based on changes in depth to the argillic horizon along transects from fields to streams and (2) calculations of mass of deposition derived from estimated 100-year upland erosion based on the universal soil loss equation and a sediment delivery ratio. Estimates of changes in depth to the argillic horizon along nine transects yielded a mean of 52 Mg·ha·−1yr−1, with a range 7.6 to 92 Mg·ha·−1yr−1. The estimated average annual rate of gross erosion minus sediment transport from the watershed was 35 Mg·ha·−1yr−1. Thus, the average annual rate of sediment deposition on this watershed during the 1880-1979 period was 35 to 52 Mg·ha·−1yr−1. These data suggest that riparian ecosystems arc important sinks for sediments.
Footnotes
Richard Lowrance is an ecologist with the Southeast Watershed Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Tifton, Georgia 31793; Julie K. Sharpe at the time of this study was a research technician with the Institute of Ecology, University of Georgia, Athens, 30602; and Joseph M. Sheridan is a research hydraulic engineer with the. Southeast Watershed Research Laboratory. This research was supported in part by a grant from the U.S. Department of Interior as authorized by the Water Research and Development Act of 1978.
- Copyright 1986 by the Soil and Water Conservation Society