Terrain bowen ratio (Heat Overlay)

Icon	Attribute	Unit	Layer	Range	Description
	BOWEN_RATIO	ratio	Surface		Describes the rate of heat transfer for a surface that has moisture as a factor.

The Bowen ratio is a property of a surface, specifically the ratio between two types of heat transfer (sensible heat and latent heat). The wetter the surface, the lower the ratio.

Notes

• The DPRA Heat stress report uses only two possible values for the Bowen ratio: 0.4 and 3.0.
• Terrains such as grassland and functions such as trees and vegetation generally have a ratio of 0.4. Other terrains and functions have a ratio of 3.0.
• Water is special in the sense that during the day the ratio is 0.4 and at night the ratio is 3.0. These values are based on the DPRA Heat stress report and cannot be modified.

See also

• Bowen ratio (Heat Overlay)
• Bowen ratio result type (Heat Overlay)
• PET formulas (Heat Overlay)

References

---

Heat Module

Heat Module

Tutorials

Overview

Theory

Benchmarks

Group

Model attributes

Model attributes

Daily average radiation • Daily average wind speed • Daily maximum temperature • Daily minimum temperature • Dates • Exclude buildings • Exclude water • Exclude foliage height m • Foliage areas • Hourly humidity • Hourly radiation • Hourly temperature • Max shadow distance • Sun altitude • Sun azimuth • Sun daily motion • Wind direction • Wind speed • Wind decline angle

Building attributes

Bowen ratio • Foliage height • Foliage crown factor • Vegetation fraction

Prequels

Building elevation • Foliage height • Terrain elevation

Related

Calculation models and formulas • Feature attributes • Model attributes • Result types

Heat Module

Tutorials

Overview

Theory

Benchmarks