Design Rainfall Data System (2016)
Location
- Label:
- Not provided
- Latitude:
- 32.1 [Nearest grid cell: 32.0875 (S)]
- Longitude:
- 115.88 [Nearest grid cell: 115.8875 (E)]
IFD Design Rainfall Depth (mm)Intensity (mm/h)
Issued: 20 September 2024
Rainfall depthintensity for Durations, Exceedance per Year (EY), and Annual Exceedance Probabilities (AEP).
FAQ for New ARR probability terminology
Table
| Annual Exceedance Probability (AEP) | |||||||
|---|---|---|---|---|---|---|---|
| Duration | 63.2% | 50%# | 20%* | 10% | 5% | 2% | 1% |
| 1 min | 1.79 | 1.98 | 2.58 | 3.01 | 3.45 | 4.05 | 4.54 |
| 2 min | 3.15 | 3.44 | 4.40 | 5.10 | 5.80 | 6.79 | 7.60 |
| 3 min | 4.21 | 4.62 | 5.94 | 6.89 | 7.86 | 9.23 | 10.3 |
| 4 min | 5.09 | 5.59 | 7.23 | 8.40 | 9.61 | 11.3 | 12.7 |
| 5 min | 5.83 | 6.41 | 8.33 | 9.71 | 11.1 | 13.1 | 14.7 |
| 10 min | 8.46 | 9.34 | 12.2 | 14.3 | 16.4 | 19.3 | 21.6 |
| 15 min | 10.2 | 11.3 | 14.8 | 17.3 | 19.8 | 23.2 | 26.0 |
| 20 min | 11.6 | 12.8 | 16.7 | 19.5 | 22.3 | 26.2 | 29.2 |
| 25 min | 12.7 | 14.0 | 18.2 | 21.2 | 24.3 | 28.5 | 31.9 |
| 30 min | 13.6 | 15.0 | 19.5 | 22.8 | 26.0 | 30.6 | 34.2 |
| 45 min | 15.9 | 17.5 | 22.6 | 26.4 | 30.2 | 35.5 | 39.7 |
| 1 hour | 17.7 | 19.4 | 25.1 | 29.2 | 33.4 | 39.4 | 44.3 |
| 1.5 hour | 20.5 | 22.5 | 28.9 | 33.7 | 38.7 | 45.9 | 51.8 |
| 2 hour | 22.8 | 24.9 | 32.0 | 37.4 | 43.0 | 51.2 | 58.1 |
| 3 hour | 26.4 | 28.8 | 37.0 | 43.3 | 50.1 | 60.1 | 68.6 |
| 4.5 hour | 30.5 | 33.3 | 42.9 | 50.4 | 58.6 | 70.8 | 81.3 |
| 6 hour | 33.8 | 36.8 | 47.6 | 56.1 | 65.4 | 79.3 | 91.4 |
| 9 hour | 38.9 | 42.5 | 55.1 | 65.0 | 76.0 | 92.5 | 107 |
| 12 hour | 42.9 | 46.9 | 60.9 | 72.0 | 84.1 | 102 | 118 |
| 18 hour | 49.0 | 53.6 | 69.8 | 82.3 | 95.9 | 116 | 134 |
| 24 hour | 53.7 | 58.8 | 76.5 | 89.9 | 104 | 126 | 144 |
| 30 hour | 57.5 | 63.1 | 81.9 | 95.9 | 111 | 132 | 150 |
| 36 hour | 60.9 | 66.8 | 86.5 | 101 | 116 | 137 | 155 |
| 48 hour | 66.5 | 73.0 | 94.0 | 109 | 124 | 145 | 163 |
| 72 hour | 75.6 | 82.9 | 106 | 121 | 136 | 157 | 173 |
| 96 hour | 83.5 | 91.4 | 116 | 131 | 146 | 167 | 183 |
| 120 hour | 90.8 | 99.4 | 125 | 142 | 157 | 179 | 195 |
| 144 hour | 98.0 | 107 | 135 | 152 | 169 | 192 | 210 |
| 168 hour | 105 | 115 | 144 | 164 | 182 | 208 | 228 |
| 1 day winter factor | - | 0.95 | 0.95 | 0.9 | 0.9 | 0.9 | 0.9 |
| 7 day winter factor | - | 1 | 1 | 1 | 1 | 1 | 1 |
| Annual Exceedance Probability (AEP) | |||||||
|---|---|---|---|---|---|---|---|
| Duration | 63.2% | 50%# | 20%* | 10% | 5% | 2% | 1% |
| 1 min | 108 | 119 | 155 | 181 | 207 | 243 | 272 |
| 2 min | 94.5 | 103 | 132 | 153 | 174 | 204 | 228 |
| 3 min | 84.3 | 92.3 | 119 | 138 | 157 | 185 | 207 |
| 4 min | 76.3 | 83.8 | 108 | 126 | 144 | 169 | 190 |
| 5 min | 70.0 | 77.0 | 100.0 | 116 | 133 | 157 | 176 |
| 10 min | 50.7 | 56.0 | 73.4 | 85.8 | 98.3 | 116 | 129 |
| 15 min | 40.8 | 45.1 | 59.1 | 69.0 | 79.1 | 92.9 | 104 |
| 20 min | 34.7 | 38.3 | 50.0 | 58.4 | 66.9 | 78.5 | 87.7 |
| 25 min | 30.4 | 33.5 | 43.7 | 51.0 | 58.4 | 68.5 | 76.6 |
| 30 min | 27.2 | 30.0 | 39.1 | 45.5 | 52.1 | 61.1 | 68.4 |
| 45 min | 21.2 | 23.3 | 30.2 | 35.2 | 40.2 | 47.3 | 53.0 |
| 1 hour | 17.7 | 19.4 | 25.1 | 29.2 | 33.4 | 39.4 | 44.3 |
| 1.5 hour | 13.7 | 15.0 | 19.3 | 22.5 | 25.8 | 30.6 | 34.5 |
| 2 hour | 11.4 | 12.5 | 16.0 | 18.7 | 21.5 | 25.6 | 29.0 |
| 3 hour | 8.80 | 9.60 | 12.3 | 14.4 | 16.7 | 20.0 | 22.9 |
| 4.5 hour | 6.78 | 7.39 | 9.53 | 11.2 | 13.0 | 15.7 | 18.1 |
| 6 hour | 5.63 | 6.14 | 7.94 | 9.35 | 10.9 | 13.2 | 15.2 |
| 9 hour | 4.32 | 4.72 | 6.12 | 7.23 | 8.44 | 10.3 | 11.9 |
| 12 hour | 3.57 | 3.91 | 5.08 | 6.00 | 7.01 | 8.53 | 9.86 |
| 18 hour | 2.72 | 2.98 | 3.88 | 4.57 | 5.33 | 6.46 | 7.43 |
| 24 hour | 2.24 | 2.45 | 3.19 | 3.75 | 4.34 | 5.23 | 5.98 |
| 30 hour | 1.92 | 2.10 | 2.73 | 3.20 | 3.69 | 4.41 | 5.01 |
| 36 hour | 1.69 | 1.86 | 2.40 | 2.80 | 3.21 | 3.82 | 4.32 |
| 48 hour | 1.39 | 1.52 | 1.96 | 2.27 | 2.58 | 3.03 | 3.39 |
| 72 hour | 1.05 | 1.15 | 1.47 | 1.68 | 1.89 | 2.18 | 2.40 |
| 96 hour | 0.869 | 0.952 | 1.21 | 1.37 | 1.53 | 1.74 | 1.91 |
| 120 hour | 0.757 | 0.828 | 1.04 | 1.18 | 1.31 | 1.49 | 1.63 |
| 144 hour | 0.680 | 0.744 | 0.935 | 1.06 | 1.17 | 1.34 | 1.46 |
| 168 hour | 0.626 | 0.684 | 0.859 | 0.974 | 1.08 | 1.24 | 1.35 |
Note:
# The 50% AEP IFD does not correspond to the 2 year Average Recurrence Interval (ARI) IFD. Rather it corresponds to the 1.44 ARI.
* The 20% AEP IFD does not correspond to the 5 year Average Recurrence Interval (ARI) IFD. Rather it corresponds to the 4.48 ARI.
Chart
Coefficients
| Annual Exceedance Probability (AEP) Coefficients | |||||||
|---|---|---|---|---|---|---|---|
| 63.2% | 50%# | 20%* | 10% | 5% | 2% | 1% | |
| C0 | 0.58370835 | 0.68145764 | 0.9472084 | 1.1014283 | 1.2372711 | 1.3992149 | 1.5122341 |
| C1 | 0.86296922 | 0.83153731 | 0.75652045 | 0.72069377 | 0.69410533 | 0.67126495 | 0.66119355 |
| C2 | -0.058227573 | -0.021494651 | 0.070493646 | 0.11781547 | 0.15551323 | 0.19180503 | 0.21160443 |
| C3 | -0.025721388 | -0.040804725 | -0.081104964 | -0.1037146 | -0.1230455 | -0.14348832 | -0.15623033 |
| C4 | 0.008692516 | 0.011450588 | 0.019442119 | 0.024356965 | 0.028835993 | 0.03392281 | 0.037371937 |
| C5 | -0.00097803026 | -0.0012098829 | -0.0019428278 | -0.0024326232 | -0.0029018186 | -0.0034607726 | -0.0038595959 |
| C6 | 3.8375223e-5 | 4.5694956e-5 | 7.0934693e-5 | 8.9030342e-5 | 0.0001070269 | 0.00012916872 | 0.00014548392 |
For information on how to use these coefficients to calculate design rainfall depths, please see the FAQ
Note:
# The 50% AEP IFD does not correspond to the 2 year Average Recurrence Interval (ARI) IFD. Rather it corresponds to the 1.44 ARI.
* The 20% AEP IFD does not correspond to the 5 year Average Recurrence Interval (ARI) IFD. Rather it corresponds to the 4.48 ARI.