Hernan Moreno - A VectorialModel To Compute Terrain Parameters and Solar Radiation On TIN Domains
Hernan Moreno - A VectorialModel To Compute Terrain Parameters and Solar Radiation On TIN Domains
Hernan Moreno - A VectorialModel To Compute Terrain Parameters and Solar Radiation On TIN Domains
EPS1135483
Outline
Motivation
Application Basin
TIN Properties
Solar Vector Computation
Radiation on Inclined Surfaces
Local and Remote Shading
Next Steps
Motivation
Motivation
-Elevation
- Slope
- Aspect
- Solar radiation
- Evaporation
- Transpiration
- Surface-subsurface water
interactions
- Variable saturated areas
- Solar energy potential
- Snow accumulation and melt
- Contaminant fate and transport
- Soil moisture
Insolation modeling
INSOLATION=SWdir + SWremote + SWdiffuse
Measurement
Pro
Con
Interpolation of point
measurements
Meteorologic
geostationary
satellites
Spatially-based solar
radiation models
Study Basin
THANKS
TIN properties
TIN
DEM=158,325 cells
TIN=36,436 elements
DEM
n=(P3-P1)x(P2-P1)
nz
S = arccos(nuz )
P2
z z
S' = +
x y
2
nx
n x X + n yY + n z Z + d = 0
z
P1
y
x
P3
nux
Mean
Median
-0.012
-0.0005
St. Dev.
0.042
Skewness
-0.003
nuy
Mean
Median
St. Dev.
Skewness
-0.0024
-0.0037
0.0454
0.00026
nuz
Mean
Median
St. Dev.
Skewness
0.9504
0.9879
0.9125
0.8811
Slope S
S = arccos (nuz )
Slope S'
z z
S' = +
x y
2
S'- S
S' Vs S
S
S'
Slope
Median
Skewness
4.146
13.2406
8.9125
18.386
340.861
12757
S'
4.153
14.5406
8.9851
19.044
463.487
22877
Slope Aspect
A=
nx
ny
arctan
|nx| 2
nx
Solar Vector
Topocentric Spheric System
At noon sun is at:
S o = (S ox , S oy , S oz )
S o = (0, sin ( ), cos( ))
= Triangle latitude
90 90
= Solar declination
23.45 23.45
System Rotation
As Earth rotates, So needs to be
multiplied by three rotational
matrices. Thus solar vector will be
S = rx ( )rz (w )rx ( )S o
rx ( ) = 1
sin
cos
cos
sin
rz (w) = cos
sin
0
sin
cos
0
0
1
= hour angle
S = sincos
sin
cos
cos
cos
sin
cos
cos
sin
sin
cosw
Cosine law
Direct Radiation
(w/m2)
nu
s
cos s = nu .S
When cos s <0 the element selfshades and when Sz < 0 sun is
below the horizon, so no light is
available.
sin
cos
cos
cos
sin
coscoscos + sinsin
Winter Solstice
Summer Solstice
Remote Sheltering
In process of application. Groups of mesh
elements are organized along the sun light
path and their projections tested for
remote shading.
z
SP
Shaded
elements
T1
T2
T3
T4 T5 T6
TIN centroids
T7
d=
h(2 R + h )
Next Steps
Include a diffuse radiation model based on sky-view
factors.
Add a remote reflected radiation for short wave or
high albedo areas.
Include a module for canopy light reduction and
below-canopy long wave radiation.
Include an energy balance model.
Couple a snow and evapotranspiration module.
Couple modules to ADHydro infiltration and routing
schemes.
THANKS