Estimate collectable rainwater from roof area and rainfall for rainwater harvesting systems and water-saving design.
适用于屋面雨水回收系统设计。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Rainwater harvest | W = 10·P·S·ψ | GB 50400-2016 |
| Runoff coefficient | ψ by surface | GB 50400-2016 |
| First flush & storage | First flush 2-3 mm | GB 50400-2016 |