A model for hydraulic redistribution incorporating coupled soil-root moisture transport
| Autor: | Praveen Kumar, Geremew G. Amenu |
|---|---|
| Přispěvatelé: | EGU, Publication, Civil and Environmental Engineering [Illinois] (CEE), University of Illinois at Urbana-Champaign [Urbana], University of Illinois System-University of Illinois System |
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
0106 biological sciences
Canopy 010504 meteorology & atmospheric sciences 0207 environmental engineering [SDU.STU]Sciences of the Universe [physics]/Earth Sciences 02 engineering and technology 010603 evolutionary biology 01 natural sciences lcsh:Technology lcsh:TD1-1066 Latent heat Dry season Hydraulic redistribution lcsh:Environmental technology. Sanitary engineering 020701 environmental engineering [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Water content lcsh:Environmental sciences 0105 earth and related environmental sciences General Environmental Science Transpiration Hydrology lcsh:GE1-350 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Moisture lcsh:T [SDU.OCEAN] Sciences of the Universe [physics]/Ocean Atmosphere lcsh:Geography. Anthropology. Recreation 15. Life on land [SDU.ENVI] Sciences of the Universe [physics]/Continental interfaces environment lcsh:G 13. Climate action [SDU.STU] Sciences of the Universe [physics]/Earth Sciences General Earth and Planetary Sciences Soil horizon Environmental science |
| Zdroj: | Hydrology and Earth System Sciences Discussions Hydrology and Earth System Sciences Discussions, European Geosciences Union, 2008, 12 (1), pp.55-74 Hydrology and Earth System Sciences, Vol 12, Iss 1, Pp 55-74 (2008) Hydrology and Earth System Sciences Discussions, European Geosciences Union, 2007, 4 (5), pp.3719-3769 ResearcherID |
| ISSN: | 1812-2108 1812-2116 1607-7938 |
| Popis: | One of the adaptive strategies of vegetation, particularly in water limited ecosystems, is the development of deep roots and the use of hydraulic redistribution which enables them to make optimal use of resources available throughout the soil column. Hydraulic redistribution refers to roots acting as a preferential pathway for the movement of water from wet to dry soil layers driven by the moisture gradient – be it from the shallow to deep layers or vice versa. This occurs during the nighttime while during the daytime moisture movement is driven to fulfill the transpiration demand at the canopy. In this study, we develop a model to investigate the effect of hydraulic redistribution by deep roots on the terrestrial climatology. Sierra Nevada eco-region is chosen as the study site which has wet winters and dry summers. Hydraulic redistribution enables the movement of moisture from the upper soil layers to deeper zones during the wet months and this moisture is then available to meet the transpiration demand during the late dry season. It results in significant alteration of the profiles of soil moisture and water uptake as well as increase in the canopy transpiration, carbon assimilation, and the associated water-use-efficiency during the dry summer season. This also makes the presence of roots in deeper soil layers much more important than their proportional abundance would otherwise dictate. Comparison with observations of latent heat from a flux tower demonstrates improved predictability and provides validation of the model results. Hydraulic redistribution serves as a mechanism for the interaction between the variability of deep layer soil-moisture and the land-surface climatology and could have significant implications for seasonal and sub-seasonal climate prediction. |
| Databáze: | OpenAIRE |
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