The runoff coefficient of the comprehensive rainwater volume was calculated using the standard H1 = 29.60 mm of internal runoff control rate in the study area, the standard H2 = 42.60 mm of external runoff control rate of the site the area of each catchment area, and the runoff coefficient of the comprehensive rainwater volume. From the volume method formula, the total amount of runoff inside and outside the site is 62,578.91 m3 (Table 3).
Catchment zone and storage volume
| Plot . | Catchment zone . | Design rainfall (mm) . | Land use . | Catchment zone area (m2) . | Runoff coefficient . | Total runoff control (m3) . | Total (m3) . |
|---|---|---|---|---|---|---|---|
| A | Internal catchment zone | 29.60 | Green space | 55,800 | 0.15 | 247.75 | 7,374.73 |
| External catchment zone | 42.60 | Green space | 24,000 | 0.15 | 153.36 | ||
| Residential land | 193,100 | 0.60 | 4,935.64 | ||||
| Commercial land | 51,200 | 0.65 | 1,417.73 | ||||
| Road and square land | 18,200 | 0.80 | 620.26 | ||||
| B | Internal catchment zone | 29.60 | Green space | 30,900 | 0.15 | 137.20 | 6,430.28 |
| External catchment zone | 42.60 | Green space | 11,900 | 0.15 | 76.04 | ||
| Residential land | 203,900 | 0.60 | 5,211.68 | ||||
| Road and square land | 29,500 | 0.80 | 1,005.36 | ||||
| C | Internal catchment zone | 29.60 | Green space | 41,100 | 0.15 | 182.48 | 11,965.64 |
| External catchment zone | 42.60 | Sports land | 40,400 | 0.65 | 11,186.76 | ||
| Road square land | 17,500 | 0.80 | 596.40 | ||||
| D | Internal catchment zone | 29.60 | Green space | 45,400 | 0.15 | 201.58 | 6,119.36 |
| External catchment zone | 42.60 | Green space | 21,300 | 0.15 | 136.11 | ||
| Commercial land | 180,000 | 0.65 | 4,984.20 | ||||
| Road and square land | 23,400 | 0.80 | 797.47 | ||||
| E | Internal catchment zone | 29.60 | Green space | 49,800 | 0.15 | 221.11 | 9,945.63 |
| External catchment zone | 42.60 | Commercial land | 325,100 | 0.65 | 9,002.02 | ||
| Road and square land | 21,200 | 0.80 | 722.50 | ||||
| F | Internal catchment zone | 29.60 | Green space | 49,200 | 0.15 | 218.45 | 5,583.49 |
| External catchment zone | 42.60 | Green space | 62,200 | 0.15 | 397.46 | ||
| Commercial land | 145,800 | 0.65 | 4,037.20 | ||||
| Road and square land | 27,300 | 0.80 | 930.38 | ||||
| G | Internal catchment zone | 29.60 | Green space | 130,500 | 0.15 | 579.42 | 8,544.34 |
| External catchment zone | 42.60 | Green space | 51,700 | 0.15 | 330.36 | ||
| Residential land | 119,100 | 0.60 | 3,044.20 | ||||
| Commercial land | 124,300 | 0.65 | 3,441.87 | ||||
| Road and square land | 33,700 | 0.80 | 1,148.50 | ||||
| H | Internal catchment zone | 29.60 | Green space | 23,700 | 0.15 | 105.23 | 5,709.68 |
| External catchment zone | 42.60 | Green space | 14,000 | 0.15 | 89.46 | ||
| Residential land | 173,500 | 0.60 | 4,434.66 | ||||
| Road and square land | 31,700 | 0.80 | 1,080.34 | ||||
| I | Internal catchment zone | 29.60 | Green space | 203,100 | 0.15 | 901.76 | 901.76 |
| Total | 2,937,100 | 62,578.91 |
| Plot . | Catchment zone . | Design rainfall (mm) . | Land use . | Catchment zone area (m2) . | Runoff coefficient . | Total runoff control (m3) . | Total (m3) . |
|---|---|---|---|---|---|---|---|
| A | Internal catchment zone | 29.60 | Green space | 55,800 | 0.15 | 247.75 | 7,374.73 |
| External catchment zone | 42.60 | Green space | 24,000 | 0.15 | 153.36 | ||
| Residential land | 193,100 | 0.60 | 4,935.64 | ||||
| Commercial land | 51,200 | 0.65 | 1,417.73 | ||||
| Road and square land | 18,200 | 0.80 | 620.26 | ||||
| B | Internal catchment zone | 29.60 | Green space | 30,900 | 0.15 | 137.20 | 6,430.28 |
| External catchment zone | 42.60 | Green space | 11,900 | 0.15 | 76.04 | ||
| Residential land | 203,900 | 0.60 | 5,211.68 | ||||
| Road and square land | 29,500 | 0.80 | 1,005.36 | ||||
| C | Internal catchment zone | 29.60 | Green space | 41,100 | 0.15 | 182.48 | 11,965.64 |
| External catchment zone | 42.60 | Sports land | 40,400 | 0.65 | 11,186.76 | ||
| Road square land | 17,500 | 0.80 | 596.40 | ||||
| D | Internal catchment zone | 29.60 | Green space | 45,400 | 0.15 | 201.58 | 6,119.36 |
| External catchment zone | 42.60 | Green space | 21,300 | 0.15 | 136.11 | ||
| Commercial land | 180,000 | 0.65 | 4,984.20 | ||||
| Road and square land | 23,400 | 0.80 | 797.47 | ||||
| E | Internal catchment zone | 29.60 | Green space | 49,800 | 0.15 | 221.11 | 9,945.63 |
| External catchment zone | 42.60 | Commercial land | 325,100 | 0.65 | 9,002.02 | ||
| Road and square land | 21,200 | 0.80 | 722.50 | ||||
| F | Internal catchment zone | 29.60 | Green space | 49,200 | 0.15 | 218.45 | 5,583.49 |
| External catchment zone | 42.60 | Green space | 62,200 | 0.15 | 397.46 | ||
| Commercial land | 145,800 | 0.65 | 4,037.20 | ||||
| Road and square land | 27,300 | 0.80 | 930.38 | ||||
| G | Internal catchment zone | 29.60 | Green space | 130,500 | 0.15 | 579.42 | 8,544.34 |
| External catchment zone | 42.60 | Green space | 51,700 | 0.15 | 330.36 | ||
| Residential land | 119,100 | 0.60 | 3,044.20 | ||||
| Commercial land | 124,300 | 0.65 | 3,441.87 | ||||
| Road and square land | 33,700 | 0.80 | 1,148.50 | ||||
| H | Internal catchment zone | 29.60 | Green space | 23,700 | 0.15 | 105.23 | 5,709.68 |
| External catchment zone | 42.60 | Green space | 14,000 | 0.15 | 89.46 | ||
| Residential land | 173,500 | 0.60 | 4,434.66 | ||||
| Road and square land | 31,700 | 0.80 | 1,080.34 | ||||
| I | Internal catchment zone | 29.60 | Green space | 203,100 | 0.15 | 901.76 | 901.76 |
| Total | 2,937,100 | 62,578.91 |