HR: 0800h
AN: H31C-1324    [Abstracts]
TI: Can Basin-scale Recharge be Estimated Reasonable with Water Balance Models?
AU: Faust, A E
EM: aefaust@hotmail.com
AF: Hydrology and Water Resources University of Arizona, 1133 E. North Campus Drive, Tucson, AZ 85721-0011 United States
AU: * Ferre, T P
EM: ty@hwr.arizona.edu
AF: Hydrology and Water Resources University of Arizona, 1133 E. North Campus Drive, Tucson, AZ 85721-0011 United States
AU: Schaap, M G
EM: mschaap@ussl.ars.usda.gov
AF: George E. Brown, Jr. Salinity Laboratory, 450 W. Big Springs Road, Riverside, CA 92507 United States
AB: We examine in-place recharge as an example of the complex, basin-scale hydrologic processes that are being represented with simplified numerical models. The rate and distribution of recharge depend on local meteorological conditions and hydrogeologic properties. The pattern of recharge is defined predominantly by the distribution of net precipitation (precipitation less evapotranspiratoin). Different pedotransfer functions predict different fractions of net precipitation that become recharge at a given location. These differences can often be explained based on the characteristics of the PTF. But, because of the complex averaging that occurs across a basin, the combined effects of meteorological variation and soil textural variation on the basin-wide recharge rates cannot be predicted based on examination of the characteristics of different PTFs. In fact, we show that the same basin-scale numerical model, using identical inputs and modeling options, can produce almost an order of magnitude variation in predicted basin total recharge depending upon the choice of PTF. This suggests that sensitivity analyses should be performed the choice of constitutive relationship (e.g. pedotransfer function model) when assessing the predictive capability of basin-scale hydrologic models.
DE: 1804 Catchment
DE: 1836 Hydrological cycles and budgets (1218, 1655)
DE: 1847 Modeling
DE: 1876 Water budgets
DE: 1884 Water supply
SC: Hydrology [H]
MN: Fall Meeting 2005