Feature attributes (Heat Overlay)
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Several geopgraphical features can have attributes which can contribute to the calculations the Heat Overlay. These attributes are stored as part of the features, and are then rasterized and used on a grid cell level.
Building attributes
Building attributes can be changed individually per Building or per Building's function. In most cases, these attributes already exist as a function value.
| Icon | Attribute | Unit | Function value | Description |
|---|---|---|---|---|
| BOWEN_RATIO | ratio | Bowen ratio | Describes the rate of heat transfer for a surface that has moisture as a factor. | |
| FOLIAGE_CROWN_FACTOR | ratio | Foliage crown factor | The ratio between the height of tree trunks and the radius of the foliage of the tree. | |
| VEGETATION_FRACTION | fraction | Vegetation fraction | The amount of the surface which is considered vegetation. |
Terrain attributes
Terrains define standard vegitation features. If for any location no Building is present with the appropriate attributes, the attributes of the underlying terrain are used instead.
| Attribute | Unit | Terrain type | Description |
|---|---|---|---|
| VEGETATION_FRACTION | fraction | Surface | The amount of the surface which is considered vegetation. |
Area attributes
Areas may define additional or overwriting data, where better data than that extrapolated from buildings or terrains is available.
| Attribute | Unit | Description |
|---|---|---|
| FOLIAGE_HEIGHT | m | The top height of foliage for a surface geometry described by an Area. |
- Group
- Building attributes
- Bowen ratio • Foliage crown factor • Vegetation fraction
- Terrain attributes
- Vegetation fraction
- Area attributes
- Foliage height
- Related