HR: 1340h
AN: H33C-1454    [Abstracts]
TI: Using Baseflow to Constrain Water Table Depth Simulations in the NCAR Community Land Model (CLM)
AU: * Lo, M
EM: mlo@uci.edu
AF: Department of Earth System Science, UC-Irvine, Croul Hall, Department of Earth System Science, University of California, Irvine, Irvine, CA 92697, United States
AU: Yeh, P
EM: patyeh@rainbow.iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, University of Tokyo, Institute of Industrial Science, University of Tokyo, Tokyo, 113-8656, Japan
AU: Famiglietti, J
EM: jfamigli@uci.edu
AF: Department of Earth System Science, UC-Irvine, Croul Hall, Department of Earth System Science, University of California, Irvine, Irvine, CA 92697, United States
AB: Several recent studies have shown the importance of representing groundwater in land surface hydrologic simulations. However, optimal methods for model calibration in order to realistically simulate baseflow and groundwater depth have received little attention. Moreover, due to model parameter interactions, various parameter combinations are found to exhibit equifinality in simulated total runoff. In this study a simple lumped groundwater model was incorporated into the Community Land Model (CLM), in which the water table is interactively coupled to soil moisture through the groundwater recharge fluxes. The coupled model (CLMGW) is successfully validated in Illinois against a 22-year (1984~2005) monthly observational dataset. The advantage obtained from incorporating baseflow calibration in addition to traditional calibration based on measured streamflow alone is demonstrated. Using the optimal Pareto parameter sets identified from baseflow and total flow calibration, the flow partitioning and water table depth simulation by the CLMGW are improved, and the equifinality problem is alleviated. For other regions that lack observations of water table depth, the baseflow estimates can be used to enhance parameter estimation. The calibrated CLMGW is applied to the entire US to study the impact of groundwater on land hydrologic memory.
DE: 1829 Groundwater hydrology
DE: 1830 Groundwater/surface water interaction
DE: 1833 Hydroclimatology
DE: 1836 Hydrological cycles and budgets (1218, 1655)
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
SC: Hydrology [H]
MN: 2007 Fall Meeting