HR: 09:30h
AN: H21B-06    [PDF]
TI: On the Importance of Linear vs Non-Linear Response in Estimating Base Flow Features for Ungauged Catchments in Southern Texas
AU: * Anderson, R
EM: richard.anderson@noaa.gov
AF: Hydrology Laboratory National Weather Service NOAA, 1325 East West Highway, Silver Spring, Md 20910 United States
AU: Koren, V
EM: victor.koren@noaa.gov
AF: Hydrology Laboratory National Weather Service NOAA, 1325 East West Highway, Silver Spring, Md 20910 United States
AU: Smith, M
EM: michael.smith@noaa.gov
AF: Hydrology Laboratory National Weather Service NOAA, 1325 East West Highway, Silver Spring, Md 20910 United States
AU: Seo, D
EM: dongjun.seo@noaa.gov
AF: Hydrology Laboratory National Weather Service NOAA, 1325 East West Highway, Silver Spring, Md 20910 United States
AB: Various equations have been derived and applied in the study of groundwater base flows. Many studies have confirmed the applicability of a linear storage-discharge relationship in describing groundwater outflows into stream channels from adjoining aquifers. This result has been used in studies of base flow to estimate various catchment-scale, effective hydraulic parameters such as saturated hydraulic conductivity, drainable porosity, and base flow recession constant. However, other studies have found that a nonlinear formulation of catchment response is more appropriate, and an explanation of this difference from a physical basis remains an unsolved problem. In a study of six catchments in southern Ohio, eastern Kentucky, and southern West Virginia (within the Ohio River Forecast Center of the National Weather Service), preliminary results showed that two catchments exhibited nonlinear recession behavior, while the others behaved in a linear fashion. As judged by flow statistics and hydrograph comparison, Sacramento model performance based on a method for a priori parameter estimation was better for the two non-linear catchments than for the linear catchments. In particular, base flow recession parameters were significantly better for the non-linear catchments. Better physical understanding of this difference could lead to improved a priori estimation of base flow parameters. However, the potential to do so is increased (1) by examining a different geographical region and (2) analyzing a larger sample of catchments. In this paper, a set of 23 catchments in southern Texas is examined in order to further explore the occurrence and significance of linear vs. nonlinear catchment hydraulic behavior. We discuss implications for improving Sacramento a priori parameter estimates as well as regionalization of its parameters.
DE: 1829 Groundwater hydrology
DE: 1860 Runoff and streamflow
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2003 Fall Meeting