HR: 1340h
AN: A53A-0869    [Abstracts]
TI: Role of soil water retention relations in a climate-crop-soil coupled regional model
AU: Horton, R
EM: rhorton@iastate.edu
AF: Dept. Agronomy, Iowa State Univ., 2543 Agronomy, Iowa State Univ., Ames, IA 50011
AU: * Pan, Z
EM: panz@eas.slu.edu
AF: Dept. of Earth and Atmos. Sci., St. Louis Univ., 3507 Laclede Ave., St. Louis, MO 63103
AB: Soil moisture prediction is of significance for agriculture, transportation, and other activities. By coupling models of regional climate, surface hydrology, and crop development, we have established a two-way interactive agroecosystem model that projects soil moisture and other hydrological variable variations in months in advance. One of the problems with this model, however, is its persistent over-drying soil that even sometimes prevents seeds from germination in a typical year. To solve this problem, we first ran a series sensitivity experiments diagnosing the error sources, determining whether the error comes from water input to soil (i.e., rainfall), soil property (e.g., bulk density, percentage triangle) or soil hydrology formulations. Of particular concern is the soil water retention curve used in the model. It is found that the soil water retention relation typically used in the atmospheric models tends to retain less water at a give water pressure than that typically used in soil science community. We will report the model improvement after adopting a new retention relation in the model by validating the model against in-situ and remote sensing soil moisture data.
DE: 1818 Evapotranspiration
DE: 0315 Biosphere/atmosphere interactions
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting