Buildings disappear although height is low (vertical gridding into 5 sub-cells)

All around LEONARDO 4 (and previous 2014)
Post Reply
MJ_SCH
Posts: 15
Joined: Sun Dec 15, 2019 5:09 pm

Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by MJ_SCH »

Hi everybody,

i set up an Area Input File of 250x250x25 grids, using a grid size of 2m each. To find out Air Temperatures/Air Pollution Dispersion near the breathing zone, i checked the splitting option in SPACES. However, when trying to visualize the results on a height of 1.4m (following terrain), many buildings disappear although these buildings are definately not that low. It seems like the heights are not matching to what is listed in the legend settings. See examples below for 3m, 1.4m and 0.6m.

Many thanks for helping and best wishes!
Mathias
Attachments
3m
3m
1.4m
1.4m
0.6m
0.6m

Tim
Posts: 1707
Joined: Mon May 15, 2017 3:46 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by Tim »

Hi Mathias,

I am very sure that you have a terrain in your model area causing that. There are several posts about this already.
Example: Cutting with follow terrain in a k level of 4
-> 1.4 m above ground (cell without terrain)
-> 8 m above ground (cell with terrain of at least 2 m height in your model area which is above splitting)

I'd thus recommend to run without DEM or disable Splitting to avoid these irritations.

Best regards,
Tim

MJ_SCH
Posts: 15
Joined: Sun Dec 15, 2019 5:09 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by MJ_SCH »

Thank you really much! This helped me alot; i just use another grid size without splitting to get the 1.5m (for comparison). This works fine!

Best wishes,
Mathias

MJ_SCH
Posts: 15
Joined: Sun Dec 15, 2019 5:09 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by MJ_SCH »

I am sorry to disturb you one more time, but there is another problem with Leonardo. I can't display my values for air temperature with the option "auto ignore buildings", which is a fundamental step for my analysis results. The values do not change although i am clicking the update button and extracted once again. I am using a DEM and the latest ENVI-MET version.

Thank you for help!
Mathias

Tim
Posts: 1707
Joined: Mon May 15, 2017 3:46 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by Tim »

Hi Mathias,

This button only changes the legend (if checked, the values inside buildings and DEM are excluded from the legend). You could also edit the legend manually.
Did you load the ENVI-met Defaults in the Special Layer Settings to draw objects instead of the invalid values?

Best regards,
Tim

MJ_SCH
Posts: 15
Joined: Sun Dec 15, 2019 5:09 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by MJ_SCH »

Thank you! But this is exactly the problem: the buildings are not excluded from the legend, so the values stay the same. I checked the envi-met default special layer settings.

Tim
Posts: 1707
Joined: Mon May 15, 2017 3:46 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by Tim »

Hi Mathias,

I don't know why they should not be excluded in your case. Could you provide some screenshots? You can simply edit the legend manually where you are able to exclude the values.

Best regards,
Tim

MJ_SCH
Posts: 15
Joined: Sun Dec 15, 2019 5:09 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by MJ_SCH »

Here are some pictures illustrating the autofill. If i just check "auto ignore buildings", the values of the buildings as well as the legend stays the same. The lowest values are still buildings.
Attachments
autofill_withoutbuildings.PNG
autofill.PNG

MJ_SCH
Posts: 15
Joined: Sun Dec 15, 2019 5:09 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by MJ_SCH »

Of course, i could also overlay the buildings and manually set my lowest legend threshold by ignoring the building values. But this seems neither practical, nor really scientific as i have to estimate/examine the point where atmospheric air temperature starts...

Tim
Posts: 1707
Joined: Mon May 15, 2017 3:46 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by Tim »

Hi Mathias,

That is strange. It may be connected to the DEM.
I'd always recommend to create a manual legend with nice step sizes anyway. Atmospheric values seem to start above 22.5 °C, so I'd begin with that value in the legend. I don't know why that should be a scientifically invalid solution.

Best regards,
Tim

MJ_SCH
Posts: 15
Joined: Sun Dec 15, 2019 5:09 pm

Re: Buildings disappear although height is low (vertical gridding into 5 sub-cells)

Post by MJ_SCH »

Thank you, Tim! Yes, i am pretty sure its due to the DEM, which is very unfortunate...I would like to have the exact beginning and ending of the atmosphere scale (generated by the system), which is impossible with the manual technique, but it seems to be the only solution (so far :wink: )

Post Reply