Description Usage Arguments Details Value Author(s) References See Also Examples
View source: R/Function_DMMF_Simple.r
This is the simplified version of DMMF
for simple one element (cell) during a day
1 2 3 4 5  DMMF_Simple( W, L = W/cos(S), S, R, RI, ET,
P_c, P_z, P_s, theta_init, theta_sat, theta_fc,
SD, K, P_I, n_s, CC, GC, IMP, PH, D, NV, d_a = 0.005,
DK_c = 0.1, DK_z = 0.5, DK_s = 0.3, DR_c = 1.0, DR_z = 1.6, DR_s = 1.5,
Q_in = 0, IF_in = 0, SL_c_in = 0, SL_z_in = 0, SL_s_in = 0, R_type = 0)

W 
Width of an element (cell) (unit: m) 
L 
Length of an element (cell) (unit: m). If 
S 
Slope angle of an element (cell) (unit: rad) 
R 
Daily rainfall per unit area (unit: mm) 
RI 
Mean hourly rainfall intensity during a day (unit: mm/h) 
ET 
Evapotranspiration per unit area (unit: mm) 
P_c 
Proportion of clay particles in surface soil (01) 
P_z 
Proportion of silt particles in surface soil (01) 
P_s 
Proportion of sand particles in surface soil (01) 
theta_init 
Initial soil water content of entire soil profile per unit area (unit: vol/vol) 
theta_sat 
Saturated soil water content of entire soil profile per unit area (unit: vol/vol) 
theta_fc 
Soil water content at field capacity of entire soil profile per unit area (unit: vol/vol) 
SD 
Soil depth of entire soil profile (unit: m) 
K 
Saturated lateral hydraulic conductivity of entire soil profile (unit: m/d) 
P_I 
Proportion of permanent interception area of rainfall (01) 
n_s 
Manning's roughness coefficient of the soil surface (unit: s/m^(1/3)) 
CC 
Proportion of area with canopy cover (01) 
GC 
Proportion of area with pervious vegetated ground cover (01) 
IMP 
Proportion of area with impervious ground cover (01) 
PH 
Average height of vegetation or crop cover where leaf drainage start to fall (unit: m) 
D 
Average diameter of individual plant elements at the surface (unit: m) 
NV 
A number of individual plant elements per unit area (unit: number/m^2) 
d_a 
Typical flow depth of surface runoff (unit: m) 
DK_c 
Detachability of clay particles by rainfall (unit: g/J) 
DK_z 
Detachability of silt particles by rainfall (unit: g/J) 
DK_s 
Detachability of sand particles by rainfall (unit: g/J) 
DR_c 
Detachability of clay particles by surface runoff (unit: g/mm) 
DR_z 
Detachability of silt particles by surface runoff (unit: g/mm) 
DR_s 
Detachability of sand particles by surface runoff (unit: g/mm) 
Q_in 
The volume of surface runoff from outside of an element (cell) (unit: L) 
IF_in 
The volume of subsurface interflow from outside of an element (cell) (unit: L) 
SL_c_in 
The mass of clay particles from outside of an element (cell) (unit: kg) 
SL_z_in 
The mass of silt particles from outside of an element (cell) (unit: kg) 
SL_s_in 
The mass of sand particles from outside of an element (cell) (unit: kg) 
R_type 
Integer object of each rainfall type for estimating kinetic energy of direct throughfall (DT) (08) (see details) 
Detailed information about options of R_type
can be found in details of DMMF
.
This function is suitable for projecting the DMMF model for a field represented in one element during a day.
The output of the function DMMF_Simple
is a data frame that contains following numeric elements:
Q_out
: Volume of surface runoff flowing from the element (unit: L)
IF_out
: Volume of subsurface water flowing from the element (unit: L)
theta_r
: Remaining soil water content of the element (unit: vol/vol)
SL_c_out
: Mass of clay outputs from the element (unit: kg)
SL_z_out
: Mass of silt outputs from the element (unit: kg)
SL_s_out
: Mass of sand outputs from the element (unit: kg)
A
: Surface area of the element (unit: m^2)
Kwanghun Choi and Bjoern Reineking
Choi, K., Arnhold, S., Huwe, B., Reineking, B. (2017). Daily based Morgan–Morgan–Finney (DMMF) model: A spatially distributed conceptual soil erosion model to simulate complex soil surface configurations. Water, 9(4), 278.
Shin, S. S., Park, S. D., and Choi, B. K. (2016). Universal power law for relationship between rainfall kinetic energy and rainfall intensity. Advances in Meteorology, Article ID 2494681, 11 pages.
Arnhold, S., Ruidisch, M., Bartsch, S., Shope, C., Huwe, B. (2013). Simulation of runoff patterns and soil erosion on mountainous farmland with and without plasticcovered ridgefurrow cultivation in South Korea. Transactions of the ASABE, 56(2):667–679.
Morgan, R. P. C. (2005). Soil erosion and conservation. Blackwell Publishing, Malden, MA, 3rd ed. ISBN 1405117818
Morgan, R. P. C. (2001) A simple approach to soil loss prediction: a revised Morgan–Morgan–Finney model. Catena, 44(4):305–322.
DMMF
for fields and catchments with more than one element.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44  ## Not run:
## Load example data for test running DMMF_Simple function
data(Potato.Convex)
attach(Potato.Convex)
## Make toy dataset using summary statistics of field datasets of "Potato.Convex" data.
## The width and slope of the field are set according to the slope length of the convex field
## from Arnhold et al. (2013)
W = 25
L = 25
## The slope of the field is set as the average slope angle of the field from Arnhold et al. (2013)
S < pi/180 * 9
## The proportion of impervious areas are estimated as the mean value of the IMP map.
IMP < cellStats(s.map$IMP, stat='mean', na.rm=TRUE)
## "n_s" estimated using the guide value of RFR using paraplough (10cm/m)
## and conversion equation from RFR to Manning's n from Morgan and Duzant (2008).
n_s < 0.171
## Using the ridge height of the field from Arnhold et al. (2013)
## as the hydrological radius (flow depth) of the field.
d_a < 0.15
## We use dynamic variables of the 12th day that has enough rainfall to produce soil erosion.
d.var_12< d.var[12,]
## Run DMMF_Simple function
Output < DMMF_Simple( W = W, L = L, S = S, R = d.var_12$R, RI = d.var_12$RI, ET = d.var_12$ET,
P_c = s.var$P_c, P_z = s.var$P_z, P_s = s.var$P_s,
theta_init = s.var$theta_fc, theta_sat = s.var$theta_sat,
theta_fc = s.var$theta_fc, SD = s.var$SD, K = s.var$K, P_I = s.var$P_I,
n_s = n_s, CC = d.var_12$CC, GC = s.var$GC, IMP = IMP, PH = d.var_12$PH,
D = s.var$D, NV = s.var$NV, d_a = d_a,
DK_c = s.var$DK_c, DK_z = s.var$DK_z, DK_s = s.var$DK_s,
DR_c = s.var$DR_c, DR_z = s.var$DR_z, DR_s = s.var$DR_s,
Q_in = 0, IF_in = 0, SL_c_in = 0, SL_z_in = 0, SL_s_in = 0, R_type = 0)
## Print outputs.
Output
## Calculate per unit surface area
## Runoff per surface area of the field
Output$Q_out / Output$A
## Interflow per surface area of the field
Output$IF_out / Output$A
## Soil loss per surface area of the field
(Output$SL_c_out + Output$SL_z_out + Output$SL_s_out) / Output$A
## End(Not run)

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