TY - JOUR
T1 - Modeling the radiation balance within a planted trench system
AU - Kramer, Isaac
AU - Agam, Nurit
AU - Berliner, Pedro
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Micro-catchment systems (MCs) are designed to harvest and utilize
rainwater, with the aim of supporting tree growth in arid regions. While
MCs were traditionally built with shallow infiltration basins, recent
research indicates that MCs with deeper basins retain more water than
MCs with shallower basins, and that trees grown in deeper MCs outperform
those grown in shallow MCs. This may be partially because the flux of
incoming shortwave radiation reaching the surface is decreased in deeper
basins. The degree to which the incoming radiation reaching the floor of
the MC is reduced, however, depends on the system's dimensions and
orientation, geographical location, canopy geometry, soil properties,
date, and time. Existing radiation models are either capable of modeling
radiation penetration into trenches, or describe transmission of
radiation through canopy. None can describe the penetration of radiation
through canopy into a trench. The goal of our research was to model the
incoming shortwave and longwave radiation flux densities reaching a MC
floor in which trees are planted. The model calculates the incoming
shortwave and longwave radiation at any given point on the trench floor.
In calculating the incoming shortwave radiation, the model considers
direct radiation, diffuse radiation, and direct and diffuse radiation
reflected from the walls of the MC system. The model also accounts for
possible shading and attenuation of the radiation caused by the presence
of a canopy in the system. Validation of the model is performed by
comparing measured incoming shortwave radiation to modeled outputs. The
measurements are conducted at various positions within existing trenches
with width of 1 m and length of 12 m, in which three 6-year old olive
trees are grown, with 4 m spacing between trees. The flexibility of the
model and the ability to change the trench configurations will help
enable the maximization of water use efficiency inside MC systems.
AB - Micro-catchment systems (MCs) are designed to harvest and utilize
rainwater, with the aim of supporting tree growth in arid regions. While
MCs were traditionally built with shallow infiltration basins, recent
research indicates that MCs with deeper basins retain more water than
MCs with shallower basins, and that trees grown in deeper MCs outperform
those grown in shallow MCs. This may be partially because the flux of
incoming shortwave radiation reaching the surface is decreased in deeper
basins. The degree to which the incoming radiation reaching the floor of
the MC is reduced, however, depends on the system's dimensions and
orientation, geographical location, canopy geometry, soil properties,
date, and time. Existing radiation models are either capable of modeling
radiation penetration into trenches, or describe transmission of
radiation through canopy. None can describe the penetration of radiation
through canopy into a trench. The goal of our research was to model the
incoming shortwave and longwave radiation flux densities reaching a MC
floor in which trees are planted. The model calculates the incoming
shortwave and longwave radiation at any given point on the trench floor.
In calculating the incoming shortwave radiation, the model considers
direct radiation, diffuse radiation, and direct and diffuse radiation
reflected from the walls of the MC system. The model also accounts for
possible shading and attenuation of the radiation caused by the presence
of a canopy in the system. Validation of the model is performed by
comparing measured incoming shortwave radiation to modeled outputs. The
measurements are conducted at various positions within existing trenches
with width of 1 m and length of 12 m, in which three 6-year old olive
trees are grown, with 4 m spacing between trees. The flexibility of the
model and the ability to change the trench configurations will help
enable the maximization of water use efficiency inside MC systems.
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VL - 19
SP - 12085
JO - Geophysical Research Abstracts
JF - Geophysical Research Abstracts
SN - 1029-7006
ER -