Tool 14 - Using IMMIS LUFT and CALINE Models to Assess Air Quality Pollution due to Traffic
IVU Umwelt GmbH offers a comprehensive model set to evaluate traffic induced air and noise pollution. The programme system IMMIS consists of the following software packages:
The IMMIS products are mostly used in German cities and increasingly
applied in other European countries. The prices of the products range
between EURO 2500 (for IMMIS Luft) up to EURO 11200 for the entire suite
(see price list).
IMMIS - Luft, ('Luft' is the German word for 'air') is the most relevant model in the context of urban environmental planning and management. It designed to calculate the annual mean value of benzene and elemental carbon as well as the 98 percentile value of nitrogen dioxide. IMMIS-Luft only requires relatively few input data.
The following describes the necessary input data and the expected results. With this information you should be able to deterimine whether you wnat to purchase such a model.
The description of this model uses data from Berlin, Germany.
a) Type of Road
IMMIS?Luft is designed to calculate the concentration of pollutants in street canyons with uninterrupted buildings on both sides. a porosity factor can be entered to take account of gaps between buildings. The concentration calculated falls rapidly as the porosity of the street increases. The following values are needed for the calculations:
· width of the street canyon (in meters)
In Berlin estimates for the inner city are mainly based on a building height of 22 m. The width of the street canyon and the porosity are variable.
(b) Calculation Site
The characteristic values for air quality are determined using the sum of concentration values at fixed sites on both sides of the street canyon. They are assumed to be at a height of 1.5m and a distance of 1.5m from the facades of the buildings.
Taking the most common wind direction in Berlin (12%N, 22%E, 26% S and 40% W) into account, it can be expected that the concentrations would systematically be about 10% higher on the climatically unfavorable sides of roads and about 10% lower on the climatically favorable sides of roads than the values determined using IMMIS?Luft. Other configurations can be pre?set by the supplier at the request of the user.
IMMIS?Luft requires the following input data:
To determine the benzene concentration, it is assumed that benzene accounts for 6% of the total VOC. To determine the nitrogen dioxide concentration it is assumed that it accounts for 7% of the total nitrogen oxides. The emission factors are installed by the supplier on the basis of information provided by the user. The user can only change them by by?passing the interface.
The average wind speed in a built?up area at a height of 10 meters above the buildings must be given as a characteristic value for the weather. In dense urban areas on flat land this value is about 75% of the wind speed measured at 10 m above the ground in an open place or airport.
For further information, contact:
CALINE is a line dispersion model developed by the state of California, Department of Transport. CALINE 4 (Caltrans, 1989) is a dispersion model that predicts carbon monoxide (CO) impacts near roadways. Its purpose is to help planners protect public health from the adverse effects of excessive CO exposure. CALINE 4 is a simple line source Gaussian plume dispersion model. The user defines the proposed roadway geometry, worst-case meteorological parameters, anticipated traffic volumes, and receptor positions. The user must also define CO emission factors for each roadway link.
Note: The Caltrans publication, Transportation Project-Level Carbon Monoxide Protocol (CO Protocol) (Garza et al., 1997), recommends the use of CALINE 4 when a proposed transportation project fails an initial screening analysis, and therefore, requires a more detailed analysis.
The model is designed to simulate the profile of concentrations on the downwind side of roads in areas where airflow is not affected by buildings lining the street like a canyon. The concentration patterns up to 150m from the road are computed for specified short?term meteorological conditions. The wind can blow across or along the street, or at any angle to the street. For comparison with criteria for yearly means and persentiles of concentrations, climatological information of the combination of wind direction, wind speed, stability and mixing height must be provided. The user has to combine this with adequately designed sets of modeled concentrations to compile the characteristic yearly values of air pollution. As CALINE does not take into account the effects of rotating wind vortices in street canyons, which tend to produce higher concentrations than in open areas, it should be used carefully in built?up areas.
CL4 is a graphical windows-based user interface, designed to ease data entry and increase the on-line help capabilities of CALINE4. The CL4 setup program is self-contained with both programs (the CL4 interface and the CALINE4 dispersion model), so the user only needs to complete a single installation step. The original CALINE4 executable files are copied to the CL4 program directory.
View of the CALINE software
Please refer to the CALINE 4 manual which is part of this CD.
For installing the CALINE model on your computer, please click here.