> For the complete documentation index, see [llms.txt](https://docs.ladybug.tools/dragonfly-primer/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ladybug.tools/dragonfly-primer/components/6_alternativeweather/terrain.md).

# Terrain

![](/files/-MihrcDUcf7kOlEw4eYy)

![](/files/-Ma9gLv5Sse1NXA0BCiq) - [\[source code\]](https://github.com/ladybug-tools/dragonfly-grasshopper/blob/master/dragonfly_grasshopper/src//DF%20Terrain.py)

Create a Terrain object representing the land on which an urban area sits.

This includes both the geometry and the properties of the pavement within the urban area.

## Inputs

* **terrain\_geo \[Required]**

  An array of Breps or meshes that together represent the terrian. This should include the entire area of the site, including that beneath building footprints. 
* **albedo**

  A number between 0 and 1 that represents the albedo (reflectivity) of the pavement. (Default: 0.1, typical of fresh asphalt). 
* **thickness**

  A number that represents the thickness of the pavement material in meters. (Default: 0.5 meters). 
* **conductivity**

  A number representing the conductivity of the pavement material in W/m-K. (Default: 1 W/m-K, typical of asphalt). 
* **vol\_heat\_cap**

  A number representing the volumetric heat capacity of the pavement material in J/m3-K. This is the number of joules needed to raise one cubic meter of the material by 1 degree Kelvin. (Default: 1.6e6 J/m3-K, typical of asphalt). 

## Outputs

* **terrain**

  A Terrain object that can be plugged into the "DF Assign Model UWG Properties" component to specify the terrain of an urban area.