Table 4.1 Representative or widely used dry deposition schemes
Description
Limitations
Sehmel and Hodgson scheme (Sehmel 1980)
Based on fitting the wind profile and deposition
observations, the scheme pioneered the parameterization of particulate and gaseous
components
Not suitable for underlying surface conditions
in urban or higher vegetation
DERMA deposition model (Hanna et al. 1982; Baklanov and Sorensen 2001)
This model is a subsidence module developed
for the Lagrange transmission model that calculates the settling rate of particles based on the
stokes law and is computationally simple
This model only considers a few chemicals and
is difficult to couple with the Eulerian model
Slinn scheme (Slinn 1982; Kim et al. 2000)
The scheme considers the canopy as a collection cylinder with a certain collection efficiency
and considers that the surface area of the vegetation canopy affects the deposition flux. It is
used in many simple ecosystem models and
environmental assessment models
It only considers canopy turbulence and gravity deposition processes
Wesely scheme (Wesely 1989)
The scheme accounts for deposition processes
of the top cover (leaf stomata and stratum
corneum), lower cover (branch, bark) and
ground cover (soil, litter). The elements considered include the effects of temperature,
humidity, solar radiation and soil on canopy
resistances, as well as meteorological elements
(e.g. temperature, humidity, solar radiation)
It uses the prescribed vegetation and soil
parameters to characterize the underlying surfaces in different regions and may lead to
errors
Muller and Prohl scheme (Müller and Pröhl 1993)
The scheme can quickly assess the deposition
process of nuclear accidents and their consequences and begins to consider the leaf area
index to estimate the receptor surface area
The scheme is relatively simple in the way it
reconstructs the deposition process and only
sets the maximum V d threshold to different
underlying surfaces
MOBLAM model (Soloviev and Schlüssel 1994)
The model mainly simulates deposition to the
water surface, accounting for water surface
waves, bubbles and high water vapour flux and
other processes that affect V d
This model oversimplifies other types of
underlying land surfaces and likely underestimates the V d
Ruijgrok scheme (Erisman et al. 1994, 1997; Ruijgrok et al. 1997)
The observed surface SO 2 and NH 3
co-deposition phenomena are considered in the
calculation of surface resistance, and the deposition of different-sized particles to the forest
canopy is described in detail
The scheme evolves from the Slinn scheme,
oversimplifying the deposition process and
underlying surface
Meyers multilayer canopy model (Meyers et al. 1998)
This model uses a multilayer canopy radiation
transmission model (Barfield and Gerber 1979)
to calculate the amount of photosynthetically
available radiation and the ratio of sunlit/shaded
It requires very detailed vegetation canopy
morphological parameters and is thus more
commonly used in single point deposition
(continued)
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Description
Limitations
Sehmel and Hodgson scheme (Sehmel 1980)
Based on fitting the wind profile and deposition
observations, the scheme pioneered the parameterization of particulate and gaseous
components
Not suitable for underlying surface conditions
in urban or higher vegetation
DERMA deposition model (Hanna et al. 1982; Baklanov and Sorensen 2001)
This model is a subsidence module developed
for the Lagrange transmission model that calculates the settling rate of particles based on the
stokes law and is computationally simple
This model only considers a few chemicals and
is difficult to couple with the Eulerian model
Slinn scheme (Slinn 1982; Kim et al. 2000)
The scheme considers the canopy as a collection cylinder with a certain collection efficiency
and considers that the surface area of the vegetation canopy affects the deposition flux. It is
used in many simple ecosystem models and
environmental assessment models
It only considers canopy turbulence and gravity deposition processes
Wesely scheme (Wesely 1989)
The scheme accounts for deposition processes
of the top cover (leaf stomata and stratum
corneum), lower cover (branch, bark) and
ground cover (soil, litter). The elements considered include the effects of temperature,
humidity, solar radiation and soil on canopy
resistances, as well as meteorological elements
(e.g. temperature, humidity, solar radiation)
It uses the prescribed vegetation and soil
parameters to characterize the underlying surfaces in different regions and may lead to
errors
Muller and Prohl scheme (Müller and Pröhl 1993)
The scheme can quickly assess the deposition
process of nuclear accidents and their consequences and begins to consider the leaf area
index to estimate the receptor surface area
The scheme is relatively simple in the way it
reconstructs the deposition process and only
sets the maximum V d threshold to different
underlying surfaces
MOBLAM model (Soloviev and Schlüssel 1994)
The model mainly simulates deposition to the
water surface, accounting for water surface
waves, bubbles and high water vapour flux and
other processes that affect V d
This model oversimplifies other types of
underlying land surfaces and likely underestimates the V d
Ruijgrok scheme (Erisman et al. 1994, 1997; Ruijgrok et al. 1997)
The observed surface SO 2 and NH 3
co-deposition phenomena are considered in the
calculation of surface resistance, and the deposition of different-sized particles to the forest
canopy is described in detail
The scheme evolves from the Slinn scheme,
oversimplifying the deposition process and
underlying surface
Meyers multilayer canopy model (Meyers et al. 1998)
This model uses a multilayer canopy radiation
transmission model (Barfield and Gerber 1979)
to calculate the amount of photosynthetically
available radiation and the ratio of sunlit/shaded
It requires very detailed vegetation canopy
morphological parameters and is thus more
commonly used in single point deposition
(continued)
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