====== 6. AERPLOT ======

===== 6.1. Introduction to AERPLOT =====

**AERPLOT** is a supplementary tool for the atmospheric dispersion model [[AERMOD]], developed by the U.S. EPA. Its main function is to generate graphical output files for simulated concentrations at different receptors. These files, with the `.plt` extension, contain concentration data associated with specific coordinates and elevations, and can be used for graphical visualization in GIS (Geographic Information System) tools such as **QGIS**.

AERPLOT does not create maps directly but facilitates the export of simulated data for spatial interpretation. In this way, it serves as a bridge between **AERMOD's** numerical results and the visual analysis of pollutant plumes in geographic space.

===== 6.2. Graphical Visualization of Emission Plumes with AERMOD and QGIS =====

==== 6.2.1 Exporting Data from AERMOD ====

To graphically visualize the emission plumes generated by AERMOD, we will use data from the ''bloomington.plt'' file, which needs to be converted into a CSV file:

  - Open the ''bloomington.plt'' file.
  - Select all data from the point indicated in the image and copy it.

You can see an example of this in [[#Figure 1|Figure 1]].

== Figure 1 ==

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{{:figura1plt.png |Figure 1 – Copy all data from the file}}

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**Figure 1:** Copy all data from the ''bloomington.plt'' file after the header.
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Now open [[https://docs.google.com/spreadsheets/d/1Uys7gp0fs19odP6Z65yDPKujNQ6OOJkRDHR567joY-c/edit?gid=0#gid=0|google sheets]] and paste the data as shown in [[#Figure 2|Figure 2]].

== Figure 2 ==

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{{:figura2paste.png |Figure 2 – Pasting data into the spreadsheet}}

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**Figure 2:** Paste the copied AERPLOT data into the spreadsheet.
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==== 6.2.2 Formatting the Spreadsheet ====

1. Delete **Row 2** by right-clicking it and selecting ''Delete row'', as shown in [[#Figure 3|Figure 3]].

== Figure 3 ==

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{{:figura3delete.png |Figure 3 – Deleting row 2}}

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**Figure 3:** Deleting row 2 in the Google Sheets spreadsheet.
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2. Select the entire sheet (`Ctrl+A`), go to **Format > Number > Plain Text** and click it. See [[#Figure 4|Figure 4]]:

== Figure 4 ==

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{{:figura4textosimples.png |Figure 4 – Convert to plain text}}

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**Figure 4:** Convert spreadsheet data to plain text format.
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3. With **Column A** selected, go to **Data > Split text to columns**, as shown in [[#Figure 5|Figure 5]]:

== Figure 5 ==

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{{:figura5dividirtexto.png |Figure 5 – Split text to columns}}

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**Figure 5:** Splitting Column A data into multiple columns.
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4. Adjust the **first row** headers to match the data in each column, as shown in [[#Figure 6|Figure 6]]. This must be done manually, as the separation may vary.

== Figure 6 ==

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{{:figuraajustes.png |Figure 6 – Header adjustments}}

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**Figure 6:** Manually adjust the spreadsheet column headers.
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5. Save the spreadsheet as `plot.csv` in the following directory:  
   ''C:\Users\Cliente\Desktop\AermodTutorial\6.AERPLOT\''

==== 6.2.3 Visualization in QGIS ====

With the formatted spreadsheet, we can now use **QGIS** to map the pollutant dispersion.

1. If you haven't installed QGIS yet, download it from [[https://qgis.org/en/site/forusers/download.html|QGIS_Download]] and complete the installation.

2. Open QGIS and click the **Open Data Source Manager** tab as shown in [[#Figure 7|Figure 7]].

== Figure 7 ==

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{{:figra7opendata.png |Figure 7 – Open Data Source Manager}}

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**Figure 7:** Opening the QGIS data source manager.
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3. Follow the steps illustrated in [[#Figure 8|Figure 8]]:

   - Select **Delimited Text**;
   - In **File name**, open the `plot.csv` file;
   - In **Z field**, select the `ZELEV` field;
   - Click **Add**.

== Figure 8 ==

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{{:figura8delimitedtext.png |Figure 8 – Import CSV settings}}

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**Figure 8:** Importing the CSV file containing AERPLOT data.
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4. Close the import window and, on the main QGIS screen, right-click on the top bar and select **Layer Styling Panel**, as shown in [[#Figure 9|Figure 9]]:

== Figure 9 ==

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{{:figura9layer.png |Figure 9 – Open styling panel}}

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**Figure 9:** Open the layer styling panel in QGIS.
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5. Access the symbology menu as shown in [[#Figure 10|Figure 10]]. Then scroll down, click **Classify**, and finally click **Apply**, as shown in [[#Figure 11|Figure 11]]:

== Figure 10 ==

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{{:figura10graduated.png |Figure 10 – Graduated classification}}

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**Figure 10:** Choose the graduated symbology type.
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== Figure 11 ==

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{{:figura11classify.png |Figure 11 – Applying classification}}

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**Figure 11:** Apply the concentration classification.
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6. In the **Browser** panel, double-click **OpenStreetMap** to add the base map.

7. In the **Layers** panel, drag the OpenStreetMap layer to **position it below the plot layer**, as shown in [[#Figure 12|Figure 12]].

== Figure 12 ==

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{{:figura12.png |Figure 12 – Layer ordering}}

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**Figure 12:** Base map layer placed below the concentration layer.
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==== 6.2.4 Final Result ====

You will now be able to visually analyze the dispersion of the modeled **SO₂** pollutant in the **Bloomington** region. The spatial visualization allows for the identification of **areas with the highest concentrations** over time, based on the simulation data from AERMOD.

===== Attachment =====
{{ :plot.rar |}}