HR: 10:55h
AN: H31G-03 INVITED     [PDF]
TI: Nonlinearity in Storage-Discharge Relationships of Heterogeneous Hillslopes and Implications for Baseflow Recession
AU: * Brandes, D
EM: brandesd@lafayette.edu
AF: Dept of Civil & Environmental Engineeering, Lafayette College, Easton, PA 16802 United States
AU: Salvage, K M
EM: ksalvage@binghamton.edu
AF: Dept of Geol Sciences and Env Studies, Binghamton University, Binghamton, NY 13902 United States
AU: Duffy, C J
EM: cxd11@psu.edu
AF: Dept of Civil & Environmental Engineeering, Pennsylvania State University, University Park, PA 16802 United States
AB: Existing models of groundwater discharge from hillslopes and small watersheds are largely empirical or are based on analytical solutions to the Boussinesq equation. As such, the effects of partially saturated flow, hillslope shape, and heterogeneity in soil hydraulic properties have not been well studied. Numerical modeling of Richards equation is used here to examine these effects on the saturated storage-discharge relationship and on baseflow recession. Model solutions under steady rainfall conditions indicate that the saturated storage-discharge relationship can take a variety of nonlinear forms depending on hillslope shape and pattern of heterogeneity; only over small ranges of saturation can the relationship be assumed linear. Dynamic simulations are currently underway; however it is hypothesized that the inherent nonlinearity of the saturated storage-discharge relationship will result in baseflow recession time series that differ from the exponential decay model often assumed.
DE: 1829 Groundwater hydrology
DE: 1860 Runoff and streamflow
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2003 Fall Meeting