Misc Wind Calculators
Decibel Addition
(or, when 40 + 40 = 43).
Value 1 / dB
Value 2 / dB
Sum / dB
Wind Profile
Z
0
values from
WAsP
manual.
Upper height / m
Lower height / m
Roughness length, Z
0
/ m
water areas (lakes, fjords, open sea) (0.0002m)
sand surfaces (smooth) (0.0003m)
snow surfaces (smooth) (0.001m)
bare soil (smooth) (0.005m)
mown grass (0.008m)
airport runway areas (0.01m)
airport areas with buildings and trees (0.02m)
farmland with very few buildings/trees (0.03m)
farmland with open appearance (0.05m)
farmland with closed appearance (0.1m)
many trees and/or bushes (0.2m)
Southern Ontario farmland (0.25m)
shelter belts (0.3m)
suburbs (0.5m)
forest (0.8m)
city (1m)
ministry buildings / sky scrapers (1.6m)
Lower Wind Speed / ms
-1
Multiplier
Upper Wind Speed / ms
-1
Hemispherical Noise Propagation
Source Sound Power Level, L
w
/ dB
Distance / m
Destination Sound Pressure Level, L
p
/ dB
Constant
: Sound Absorption Coefficient, α / dB(A)m
-1