Social challenge/ impact linked to:

Level of importance

1 - High Importance / must have

Description

Scale as linked to D2.2 framework

• City
• Neighborhood 
• Project Area
• Street

Data source and input type

• Land use maps 
• National or local weather stations

Connection with SDGs

• Goal 11: Sustainable cities and communities
• Goal 13: Climate action

Required Data

• Volume of rainfall(mm)
• Runoff coefficient value

Expected Outputs

• mm
• Total volume of rainfall which is not absorbed by the ground. 

Calculation methods

• Runoff volume = volume of rainfall X runoff coefficient
• Runoff coefficient value 
  • this is the average percentage of rainwater that runs off that type of surface
  • values for different surfaces are as follows:
  • roof or impervious paving (such as an asphalt street) - 0.8-0.95
  • Sonoran Desert uplands (healthy indigenous landscape): range 0.20–0.70, average 0.30–0.50
  • Bare earth: range 0.20–0.75, average 0.35–0.55
  • Grass/lawn: range 0.05–0.35, average 0.10–0.25
  • For gravel use the coefficient of the ground below the gravel

Level of expertise required

• Basic

Links and references

• Front matter 10-29-09.qxd:Layout 1 (netdna-ssl.com)