Tutorial Heat Stress Project

The Heat Overlay allows users to visualize a generated Physiological Equivalent Temperature (PET) overlay, along with other intermediate overlay results. The Heat Overlay can be configured using the Wizard.

Using this tutorial you can setup a new Heat Overlay in a new or in one of your existing projects by using the Heat Overlay Wizard step by step. We advise to start a new project of the suggested area to be able to compare your project to the outcomes of the example project. If that is not releavnt for you, feel free to use one of your existing projects to work with the Heat Overlay Wizard.

Getting Started

Open the Tygron Platform, login with your username and password.
Choose New Project or select one of your existing projects. If you use an existing project you can go to the Add Heat Overlay step. Otherwise follow the instructions below first.
Enter 'Grebbedijk, Wageningen' in the Address Line and select a 750x750 m project area.
Click 'Generate Map'.

Select project area

Add Heat Overlay

Add Overlay

Hover over the button Overlays, in the Current situation tab and select Add Heat Stress.
The Heat Overlay is added to the Overlays in the left-side-panel, and in the overlay bar on the right side of the map.

Configure Wizard

Open the Wizard by clicking on the "Configuration Wizard" button on the right panel

Open Wizard

Click on "Next" in the Introduction of the Wizard.

Now you can see the steps which you will be setting up.

Step 1: Select model

In Step 1 you can choose either the new (more accurate) DPRA Model or the UNESCO Heat stress module that was used in previous releases of the Tygron Platform.

For this tutorial select the DPRA Model.

Choose model

Step 2: Choose date and time of day

In Step 2 you can select the start and end date for the PET calculation, also the specific hours. Additional paramaters can also be adjusted for the specific hours and days given.

Select August 2, 2013. You can also choose to select multiple consecutive days when using the Heat Overlay Wizard.
Select Edit and configure the hours you want to generate results for: Choose every hour from 12:00 to 18:00 pm. Each day-hour combination will become a result. This result is stored as a time-frame to relate it back to the day and time. For each day, and for each time of day, the following will be automatically generated when using the wizard:

The day and time pairs, along with the project location, will be used to automatically calculate the sun altitude and azimuth angles for each day-time pair.
The sun daily motion factor is a parameter used in the atmospheric temperature formula. It will be automatically selected from the sun motion factor table, based on the date (column) and time of day (row).

Choose next.
Now you see an overview of the sun angle at each time of day and other relevant factors. To find out more about the attributes and the impact they have on the overall system go to Heat Stress Overview. Choose next

Step3: Supply daily and hourly weather station data

Now you see an overview of the default weather station data. To learn more about how to upload weather station data go to the KNMI Weather data page and the How to import KNMI weather data into Microsoft Excel page. Download the historical hourly weather data for that station and use the data from certain columns as input. In a nutshell, using the weather data, you have to supply both Daily and Hourly Values. Check the links below to learn how you can supply these.

In this tutorial we however use the default settings; Click next.

Select days and hours
Configure hours
Weather Station data

Step 4: Select source for Foliage

In step 3 you can define how to treat the foliage in your project. You can setup how you want the foliage height and crown factor to behave and wether or not you want to visualize foliage in the Heat Overlay.

Choose 'Use foliage height areas' and Click next.
You can now choose to select or import foliage areas. For this tutorial, choose Do Nothing and click Next.

To see how foliage height and crown factor are set up in detail go to:

Foliage height
Foliage functions

Step 5: Choose the results to be visualised

In the final step you can choose which result types you want to display in the Overlay. Most users will be interested in the PET (Physiological Equivalent Temperature) but it varies from project to project. Choose all output overlays to get insight in the different components that configure the PET.

Choose which of these results will initially be shown in the menu by clicking on the "First" checkbox. The rest will be shown as a subcategory.

Input Overlays
Output overlays

Click on Finish to close the Wizard. You have succesfully setup your Heat Stress Overlay.

Explore your results

Hover over the Heat Stress Overlay on the right and its different child overlays.

You can run through the different time frame results by using the arrows in the Left corner of the 3D-world.

Heat Overlay

You can compare your results to those in the 'HitteWageningen' Project which is available standard in your project overview. Please make sure to recalculate the results in this project by using the update button in the upper left corner of your screen.

Check the Foliage child overlay: Since we chose to not use foliage data in this tutorial, the child overlay in your own project shows a blank Overlay here. The child overlay in the 'HitteWageningen' project shows a version with uploaded data. You can also see this influences the sky view significantly, as well as the PET result.
Now improve your result by running through the Heat Stress Configuration Wizard again and choosing 'Tree function height and foliage crown factor' at the step for Foliage Height and choosing all the default steps afterwards.
Can you improve your result even further by uploading detailed Foliage data?

Shade Overlay

Check the Shade child overlay. You can for example clearly see the impact of the high building in Buitenwijk Wageningen Oost.
Note that you can change the grid size of your calculation by choosing (Change Grid) in the middle of the right column in your screen. Change it from 10m to 1 m and inspect the result.