# Terrain

![](https://3405893330-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9gBkJelXEQ5LsYEl7%2Fuploads%2Fgit-blob-7606586d1a832623677b451de656e4621d11ef94%2FTerrain.png?alt=media)

![](https://3405893330-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9gBkJelXEQ5LsYEl7%2Fuploads%2Fgit-blob-ca745e61a9e7c87930a0de01aee5142bd4935b05%2FTerrain.png?alt=media) - [\[source code\]](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.