Foliage height calculation model (Heat Stress Overlay) - Revision history

Frank@tygron.nl at 13:18, 13 April 2026

2026-04-13T13:18:33Z

← Older revision		Revision as of 13:18, 13 April 2026
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	* The decline of the foliage height cannot be changed, it will always be linear.		* The decline of the foliage height cannot be changed, it will always be linear.
	* As noted above, the [[Vegetation_fraction_(Heat_Stress_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.		* As noted above, the [[Vegetation_fraction_(Heat_Stress_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.
	* {{HeatStressOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.		* {{HeatStressOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Stress Overlay)\|foliage area]]s as input.
	[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Stress Overlay)]] in the [[DPRA Heat stress report]]]]		[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Stress Overlay)]] in the [[DPRA Heat stress report]]]]

Maxim@tygron.com at 12:33, 13 April 2026

2026-04-13T12:33:10Z

← Older revision		Revision as of 12:33, 13 April 2026
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	* As noted above, the [[Vegetation_fraction_(Heat_Stress_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.		* As noted above, the [[Vegetation_fraction_(Heat_Stress_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.
	* {{HeatStressOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.		* {{HeatStressOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.
	[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]		[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Stress Overlay)]] in the [[DPRA Heat stress report]]]]

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Maxim@tygron.com at 12:32, 13 April 2026

2026-04-13T12:32:18Z

← Older revision		Revision as of 12:32, 13 April 2026
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	\|notes=		\|notes=
	* The decline of the foliage height cannot be changed, it will always be linear.		* The decline of the foliage height cannot be changed, it will always be linear.
	* As noted above, the [[Vegetation_fraction_(~~Heat_Overlay~~)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.		* As noted above, the [[Vegetation_fraction_(Heat_Stress_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.
	* {{HeatStressOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.		* {{HeatStressOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.
	[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]		[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]
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	* [[Trees and foliage tutorial]]		* [[Trees and foliage tutorial]]
	\|seealso=		\|seealso=
	* [[Foliage_result_type_(~~Heat_Overlay~~)\|Foliage (result type)]]		* [[Foliage_result_type_(Heat_Stress_Overlay)\|Foliage (result type)]]
	}}		}}
	<!--* [[FAQ_Foliage_Heat_(Overlay)\|Foliage FAQ]]-->		<!--* [[FAQ_Foliage_Heat_(Overlay)\|Foliage FAQ]]-->

	{{HeatOverlay_formula_nav}}		{{HeatOverlay_formula_nav}}

Frank@tygron.nl at 11:47, 13 April 2026

2026-04-13T11:47:50Z

← Older revision		Revision as of 11:47, 13 April 2026
Line 5:		Line 5:
	* The decline of the foliage height cannot be changed, it will always be linear.		* The decline of the foliage height cannot be changed, it will always be linear.
	* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.		* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.
	* {{~~HeatOverlay~~ warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.		* {{HeatStressOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.
	[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]		[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]

Frank@tygron.nl: Frank@tygron.nl moved page Foliage height calculation model (Heat Overlay) to Foliage height calculation model (Heat Stress Overlay)

2026-04-13T11:34:19Z

Frank@tygron.nl moved page Foliage height calculation model (Heat Overlay) to Foliage height calculation model (Heat Stress Overlay)

← Older revision	Revision as of 11:34, 13 April 2026
(No difference)

Frank@tygron.nl at 10:45, 13 February 2025

2025-02-13T10:45:44Z

← Older revision		Revision as of 10:45, 13 February 2025
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	<!--* [[FAQ_Foliage_Heat_(Overlay)\|Foliage FAQ]]-->		<!--* [[FAQ_Foliage_Heat_(Overlay)\|Foliage FAQ]]-->

	{{~~Template:~~HeatOverlay_formula_nav}}		{{HeatOverlay_formula_nav}}

Frank@tygron.nl at 10:45, 13 February 2025

2025-02-13T10:45:38Z

← Older revision		Revision as of 10:45, 13 February 2025
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	Knowing where foliage is present and at what height it is situated for each grid cell of a [[Heat Overlay]] is important and used in the [[Shade calculation model (Heat Overlay)\|Shade]] and [[Sky view factor calculation model (Heat Overlay)\|Skyview]] calculation models.		{{: Foliage height calculation model}}

	~~The foliage height for each grid cell can be determined in a number of ways:~~
	* By supplying the [[area]]s which each hold the [[Foliage height (Heat Overlay)\|height of foliage]] for the whole polygon of a particular area.
	* By supplying a [[foliage height prequel (Heat Overlay)\|prequel Grid Overlay]] which holds the foliage heights as a grid.
	* By calculating foliage based on the height of foliage [[function]]s and their [[Foliage crown factor (Heat Overlay)\|foliage crown factor]].

	~~The options for determining the foliage height are mutually exclusive. Only one option will determine the foliage height.~~

	It depends on the available data and the use case which option you will choose as a user. When developing future scenarios in which other users can add foliage to unknown location, it is advised to use the Foliage crown factor option.

	~~==Rasterization==~~
	Regardless of the source for foliage heights, as a preparatory step for the calculations the data is transformed into a rasterized form. The end-result can be accessed via the [[foliage result type (Heat Overlay)\|foliage result type]]

	~~===Foliage Areas ===~~
	~~In case you have vector data containing foliage areas with foliage heights, you can import these by following the how-to~~: ~~[[How to import foliage height areas]].~~

	~~===Foliage Grid Overlays===~~
	~~In case you have a Grid Overlay with~~ Foliage height~~, you can create a GeoTiff Overlay and use it as a [[Prequels (Heat Overlay)\|prequel Overlay]] to configure the foliage height.~~

	~~===Functions===~~
	~~In the case that foliage heights are derived from [[Function]]s with a [[foliage crown factor (Heat Overlay)\|foliage crown factor]], a~~ calculation ~~is performed for all foliage in the project. A building is deemed foliage when it meets the following criteria:~~
	* The building has the [[Function Category]] NATURE.
	* The building has its [[Function Value]] for the [[foliage crown factor (Heat Overlay)\|foliage crown factor]] greater than 0.
	* The building is not [[exclude buildings (Heat Overlay)\|excluded]] from calculations.

	~~The calculation of foliage heights for all grid cells is then performed as follows:~~
	# For each grid cell with foliage, the foliage diameter is calculated by multiplying the height of the foliage [[building]] with the [[foliage crown factor]]. Dividing the diameter by 2 yields the radius.
	~~# This radius and foliage height is stored for each grid cell.~~
	~~# For each grid cell i, each surrounding cell j within a search range of 100 meters is checked for a foliage height.~~
	# In case the foliage height > 0, and the grid cell i is within range of the foliage diameter of cell j, the calculated foliage height for cell i is based on the distance from the center of the tree and a linear declining foliage height. The linear decline is 1:1 and currently cannot be set to a different decline. See the image below.
	~~# The maximum foliage height is eventually stored as the foliage height of that cell.~~
	~~# Additionally, the [[Bowen ratio (Heat Overlay)\|Bowen ratio]] is set to 0.4 and the [[Vegetation fraction (Heat Overlay)\|vegetation fraction]] is set to 1.~~
	~~[[File:Foliage_trunk.png\|400px]][[File:Foliage crown factor.png\|400px]][[File:Foliage top.png\|400px]]~~

	{{article end		{{article end

Frank@tygron.nl at 14:55, 4 November 2024

2024-11-04T14:55:27Z

← Older revision		Revision as of 14:55, 4 November 2024
Line 38:		Line 38:
	* The decline of the foliage height cannot be changed, it will always be linear.		* The decline of the foliage height cannot be changed, it will always be linear.
	* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.		* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.
	* {{HeatOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[foliage area]]s as input.		* {{HeatOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[Foliage areas (Heat Overlay)\|foliage area]]s as input.
	[[File:dpra_foliage_areas\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]		[[File:dpra_foliage_areas.png\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]

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Frank@tygron.nl at 14:54, 4 November 2024

2024-11-04T14:54:45Z

← Older revision		Revision as of 14:54, 4 November 2024
Line 39:		Line 39:
	* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.		* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.
	* {{HeatOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[foliage area]]s as input.		* {{HeatOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[foliage area]]s as input.
	[[File:dpra_foliage_areas\|thumb\|right\|[[Foliage ~~area~~]]s in the DPRA report]]		[[File:dpra_foliage_areas\|thumb\|right\|[[Foliage areas (Heat Overlay)]] in the [[DPRA Heat stress report]]]]

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Frank@tygron.nl at 14:52, 4 November 2024

2024-11-04T14:52:33Z

← Older revision		Revision as of 14:52, 4 November 2024
Line 38:		Line 38:
	* The decline of the foliage height cannot be changed, it will always be linear.		* The decline of the foliage height cannot be changed, it will always be linear.
	* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.		* As noted above, the [[Vegetation_fraction_(Heat_Overlay)\|vegetation fraction]] and Bowen ratio are also changed when the foliage height is set to a positive height. This means it is also set when a GeoTIFF or areas are used to set the foliage height.
			* {{HeatOverlay warning foliage wind}} The original [[DPRA Heat stress report]] uses relatively large [[foliage area]]s as input.
			[[File:dpra_foliage_areas\|thumb\|right\|[[Foliage area]]s in the DPRA report]]

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