Import trees and assign correct height

DPBakker.Arcadis

Dear community,

For a municipality we need to define the shade percentage. The municipality has provided us with a detailed tree database with different types and heights of trees. I'm able to import the trees, but cannot yet select an attribute as a height value. Thus, the default height value of 12 m for Standaard Loofboom is given. How can I assign the correct height value to the trees?

I had hoped there would be a function to alter the height per tree based on an attribute value. In my datafile, the attribute MAX shows the maximum tree height value. My current solution/workflow is to import trees and assign them to one of seven categories. In MS Excel, I first average the value per class. The Tygron analysis after that goes as follows:

Step 1: Remove trees

- Select multiple buildings

- Input Category: Openbaar groen. Action: REMOVE. Select Entire map

Step 2: Create function values

- Buildings, Functions&Tools, Edit function values

- Category Filter: NATURE

- Duplicate Standaard loofbomen (keep Standaard loofbomen as back-up) for the amount of categories.

- Rename to Standaard loofbomen {filtervalue}, e.g. Standaard Loofbomen <6 m.

- Floor Height M: Change to {filtervalue}, e.g. 3,84 m

Step 3: Import trees

- Geo Import 

- Buildings

- Import a GeoJSON File

- Select local File (e.g. trees.geojson)

- Filter Features, Filter Based on Attribute Value

○ MAX, X < 6

○ MAX, 6 <= X < 9

○ MAX, 9 <= X < 12

○ MAX, 12 <= X < 15

○ MAX, 15 <= X < 18

○ MAX, 18 <= X < 24

○ MAX, X >= 24

- Naming, Prefix with number (Boom{filtervalue})

- Import Attribute, MAX (this is the maximum tree height value, derived from elevation maps)

- Assign Functions, One Function: Standaard loofbomen {filtervalue}

Step 3 has to repeated seven times to import all trees per category. Thus, it would save a lot of time to import the trees only once and then change the Height based on a given attribute (maybe via a TQL or something else).

Rudolf

Hi there!

It's an easy detail to miss, but the heights of trees are dictated by the Attribute FLOOR-HEIGHT-M. This usually refers to the height of floors of constructions such as houses or factories, but in the case of objects like trees or wind turbines, this attribute dictates the height of the object.

While importing, if all your trees have the relevant attribute set to the value which mathes the exact intended height, you can have that attribute map to FLOOR-HEIGHT-M during the attributes step of the geo import wizard. This is the step where you can check and uncheck attributes so that they are or are not included while importing. The same step allow allows renaming the attributes (mapping them), so that they match the relevant attributes in the software.

Will this work for you?

Regards!

DPBakker.Arcadis

Hi Rudolf,

Thank you very much, this worked! During step 6 of the Geo Data Wizard I can indeed select all the attributes. But only by carefully changing the TQL name of the imported height attribute to FLOOR HEIGHT M (either use _ or spaces) I was able to import it. So a great improvement!