| General
input data The model input data consist of UBA emission factors, a 10-year climatologic time series of the DWD (German Weather Service), a set of daily, weekly and annually value variations as well as of street segment specific data concerning the traffic situation and traffic census data. A number of required input data may be available within the program system IMMIS  .
For example, the emissions may be calculated using IMMISem.
In addition, concentrations calculated using IMMISnet
are used as background concentration values in
IMMISluft.As meteorological input data IMMISluft requires a frequency distribution for the factors wind direction, wind velocity and stability. The current mean wind velocity used in the calculation is a reference wind speed according to the meteorological input data set or a derived wind speed reduced by roughness. Street segment specific input data There are data required describing the street geometry. The segement coordinates are useful information to calculate concentrations. The segment length as well as the segment orientation can be derived from the coordinates of the start and end point of the segment. The segment length is necessary to determine the porosity in case of an open building structure. The coordinates are also used when visualizing in a GIS. The building structure of an street segment is characterized by the distance, height and porosity. Furthermore there are traffic data required for every street segment. This includes the average daily volume of traffic, parts of heavy trucks, driving patterns and part of daily Stop&Go. |
