Publication Abstracts
Puma et al. 2006
, M.A. Celia, I. Rodriguez-Iturbe, J.M. Nordbotton, and A.J. Guswa, 2006: Threshold scales for spatially averaged soil moisture and evapotranspiration with rainfall heterogeneity. In Proceedings of XVI International Conference on Computational Methods in Water Resources. P.J. Binning, P.K. Engesgaard, H.K. Dahle, G.F. Pinder, and W.G. Gray, Eds., Technical University of Denmark.
An outstanding issue in ecohydrologic modeling is scaling nonlinear plant-level interactions among soil, vegetation, and water to larger spatial scales. Spatial heterogeneity in precipitation and vegetation exert significant control on scaling properties, especially in water-limited ecosystems. Recent investigations have demonstrated that relationships between variables controlling soil-moisture dynamics are hysteretic at larger averaging scales, even when unique relationships are imposed at the plant level. The evolution of these relationships with increasing averaging area depends on the properties of the ecosystem. The goal of this investigation is to identify a threshold scale for spatially averaged soil moisture and evapotranspiration beyond which the characteristics of the non-unique relationships will vary only slowly as averaging area becomes larger. The threshold scale, which is analogous to the concept of a representative elementary area (REA), enables identification of a large- scale relationship that is meaningful with respect to ecosystem properties. We focus on the case of spatial and temporal heterogeneity of rainfall due to thunderstorms in Texas. Simulation results demonstrate that, if vegetation is homogeneous, REAs likely exist at scales between 10 and 100 times the mean size of storm rain cells. However, if heterogeneous vegetation cover occurs, then a threshold scale is not reached before violating the assumption of a stationary rainfall process for the Texas thunderstorm case.
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BibTeX Citation
@inproceedings{pu03000u,
author={Puma, M. J. and Celia, M. A. and Rodriguez-Iturbe, I. and Nordbotton, J. M. and Guswa, A. J.},
editor={Binning, P. J. and Engesgaard, P. K. and Dahle, H. K. and Pinder, G. F. and Gray, W. G.},
title={Threshold scales for spatially averaged soil moisture and evapotranspiration with rainfall heterogeneity},
booktitle={Proceedings of XVI International Conference on Computational Methods in Water Resources},
year={2006},
publisher={Technical University of Denmark},
address={Copenhagen},
}
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RIS Citation
TY - CPAPER ID - pu03000u AU - Puma, M. J. AU - Celia, M. A. AU - Rodriguez-Iturbe, I. AU - Nordbotton, J. M. AU - Guswa, A. J. ED - Binning, P. J. ED - Engesgaard, P. K. ED - Dahle, H. K. ED - Pinder, G. F. ED - Gray, W. G. PY - 2006 TI - Threshold scales for spatially averaged soil moisture and evapotranspiration with rainfall heterogeneity BT - Proceedings of XVI International Conference on Computational Methods in Water Resources PB - Technical University of Denmark CY - Copenhagen ER -
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