HR: 1330h
AN: H42G-1155    [PDF]
TI: Spatial Dynamics of Soil Moisture at Hillslope and Small Catchment Scales
AU: * Band, L E
EM: lband@email.unc.edu
AF: University of North Carolina, CB#3220, Chapel Hill, NC 27599 United States
AU: Kenworthy, S
EM: stk@umbc.edu
AF: Baltimore Ecosystem Study, 134 TRC Building UMBC, Baltimore, MD 21227
AU: Tague, C
EM: ctague@mail.sdsu.edu
AF: Department of Geography, San Diego State University, San Diego, CA 92182.4493 United States
AU: Tague, C
EM: ctague@mail.sdsu.edu
AF: Baltimore Ecosystem Study, 134 TRC Building UMBC, Baltimore, MD 21227
AU: Tenenbaum, D
EM: davidten@email.unc.edu
AF: University of North Carolina, CB#3220, Chapel Hill, NC 27599 United States
AU: Groffman, P M
EM: groffmanp@ecostudies.org
AF: Institute for Ecosystem Studies, Box AB, Millbrook, NY 12545 United States
AB: We present observations of soil moisture patterns in relation to topography in a small, Mid-Atlantic Piedmont basin over a full annual cycle, including a period of severe drought. We document spatial variation in near surface (upper 6 cm) soil moisture, which has an important influence on soil biogeochemical cycling, at a local (25 m2) scale and examine topographic patterns of plot level soil moisture means and variances at the catchment scale. These field observations were collected in support of a broader project investigating the role of spatial variation in soil moisture and hydrologic connectivity on the transport and biogeochemical cycling of nitrogen in the watershed. Local mean soil moisture in upland areas closely followed a linear trend with the topographic wetness index. Bottomland mean soil moisture typically remained above this linear trend with topographic wetness index, and bottomland soil moisture variance at the plot level was typically much higher than the variance in the uplands. Local variance of soil moisture was highest under intermediate values of soil moisture, decreasing under both wet and dry conditions. We show that both local mean and variance of near surface soil moisture have important sets of controls on nitrogen cycling and export from the basin, and that the spatial and temporal patterns of these parameters in the bottomland are most closely coupling with the biogeochemical behavior of the stream.
DE: 1806 Chemistry of fresh water
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2003 Fall Meeting