AirWare
air quality assessment & management
Reference and User Manual
AirWare   On-line Reference Manual
  Release Level 7.0
  Revision Level beta
  Release Date 2015 03

Last modified on:   Monday, 13-Jul-15 20:02 CEST

Roughness Length

Land use surface characteristics and associated roughness (length) as well as UV albedo are important inputs for CAMx.

CAMx landuse categories and the default surface roughness values (m) assigned to each category by season. Winter is defined for conditions where there is snow present; winter months with no snow are assigned to the Fall category. Roughness for water is taken as the maximum of the baseline value given in the table, and the function Z0 = 0.000002 w**2.5 , where w is surface wind speed (m/s).

The listed UV albedo values can be used to assign UV albedo from landuse data in preparing the albedo/haze/ozone (AHO) input file.

Surface Roughness (in meters) and UV Albedo by land cover and season

Number Land cover Spring Summer Fall Winter UV Albedo
1 Urban 1.00 1.00 1.00 1.00 0.08
2 Agricultural 0.03 0.20 0.05 0.01 0.05
3 Rangeland 0.05 0.10 0.01 0.001 0.05
4 Deciduous forest 1.00 1.30 0.80 0.50 0.05
5 Coniferous forest, wetland 1.30 1.30 1.30 1.30 0.05
6 Mixed forest 1.15 1.30 1.05 0.90 0.05
7 Water 0.0001 0.0001 0.0001 0.0001 0.04
8 Barren land 0.002 0.002 0.002 0.002 0.08
9 Non-forested wetlands 0.20 0.20 0.20 0.05 0.05
10 Mixed agricultural/range 0.04 0.15 0.03 0.006 0.05
11 Rocky (with low shrubs) 0.30 0.30 0.30 0.15 0.05


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