Ground infiltration md (Water Overlay)

Icon	Attribute	Unit	Range	Description
	GROUND_INFILTRATION_MD	m/day		The speed at which water can flow vertically from the surface to the underground unsaturated zone.

Buildings with a significant GROUND_INFILTRATION_MD are known as porous buildings.

Some buildings can be porous or open and can allow water to infiltrate into the underground unsaturated zone. Examples of such buildings are grass, bushes, trees or specialized roads and parking lots.

The speed at which water can infiltrate is dependent on both the infiltration properties of the buildings as well as on the underlying surface terrain and underground terrain. The infiltration value that will be used in the grid cell will be the minimum value of the infiltration values of the building, the surface terrain, and the underground terrain. This also means that if any of the infiltration values is 0, water cannot infiltrate into the underground unsaturated zone.