# [SOURCES] Section

## Purpose

Sources are the most complex input data in ENVI-met as the following information must be provided:

• Location of the sources
• Emission rate
• Type of emitted component

The location of the sources is defined in the Area Input File and their emission rates and heights are defined in the database SOURCES.DAT in a Local Database. Finally, the type of source (gas, particle) is defined in the configuration file.

At the moment, you can only have one sort of emitted component in the model (but you can have different sources at different locations). So the settings in the configuration file are applying to ALL sources in the model.

One special case are CO2 sources. As ENVI-met must calculate the CO2 concentration in the air when using the A-gs model (see section [PLANTMODEL]), CO2 sources will be added to the internal CO2 model, not to the gas/particle model.

ENVI-met can handle sources of particulate matter (PM) as well as gas sources. For the latter one, no chemical transformations are calculated in the model. The simulation of particle dispersion includes sedimentation and deposition at surfaces and plant leafs depending on the size and density of the particles.

00: [SOURCES] _____________Type of emitted gas/particle
01: Name of component                             =PM10
02: Type of component                             =PM
03: Particle Diameter in [µm] (0 for gas)         =10
04: Particle Density [g/cm³]                      =1
05: Update interval for emission rate [s]         =600

## What do the lines mean?

#### 01: Name of component

Name of component (only for information use)

#### 02: Type of component

Defines of what kind the sources are.

Valid types in Version 4.0 are:

"PM":    Particulate matter
"CO":    Carbon oxide
"CO2":   Carbon dioxide
"NO":    Nitrogen oxide
"NO2":   Nitrogen dioxide
"SO2":   Sulfur dioxide
"NH3":   Ammonia
"H2O2":  Hydrogen peroxide

Please enter the IDs exactly as shown above!
The types of source are fixed in the code of ENVI-met. If you need to simulate a component that is not included in the list, chose the component with next similar properties. Click here for more information

#### 03: Particle Diameter in micrometre

Diameter of particle if your emitted substance is particulate matter. (only for particles)

#### 04: Particle Density in g/cm³

Density of particle if your emitted substance is particulate matter.
For normal particles, 1 g/cm³ is a good assumption.

#### 05: Update interval for emission rate in s (Default 600)

For each hour of the day the emission rate of the sources can vary (see SOURCES.DAT).
Enter in which time intervals the emission rate should be updated in the model.
Using too long intervals can cause numerical problems!