Flood Risk and Vulnerability Analysis Project - Atlantic Climate ...

Storm Duration
Storm Duration
Development of Projected Intensity-Duration-Frequency Curves
for Corner Brook and Goulds/Petty Harbour, Newfoundland May 16, 2012
5.2 Projections of Precipitation Intensities
Table 5-3 through Table 5-5 show the precipitation intensities from the historical IDF
curves from Environment Canada for the Deer Lake, St. John’s A, and the St. John’s
Composite record, respectively. These precipitation intensities were adjusted by the
projected change, as described in Section 4.6, to obtain the projected precipitation
intensities for each of the 2020, 2050 and 2080 time periods. These are shown for the
Deer Lake Station in Table 5-6 to Table 5-8, for the St. John’s A station in Tables 5-9 to
5-11 and for the St. John’s Composite record in Tables 5-12 to 5-14. Projected
precipitation intensities are reported as the maximum, mean and 90 th percentile of the
48 values estimated.
Table 5-3 - Historical IDF Table, Deer Lake Station, Precipitation intensities over the specified
duration, mm/hr
Return period (years)
2 5 10 20 25 50 100
5 min 47.3 69.5 84.1 98.2 102.7 116.4 130.0
10 min 34.3 48.6 58.2 67.3 70.2 79.1 87.9
15 min 27.9 38.3 45.1 51.7 53.8 60.2 66.6
30 min 19.7 25.4 29.2 32.8 33.9 37.5 41.0
1 hr 13.4 16.8 19.1 21.3 21.9 24.1 26.2
2 hr 9.4 12.2 14.1 15.8 16.4 18.1 19.9
6 hr 5.0 6.1 6.8 7.5 7.7 8.4 9.1
12 hr 3.1 3.7 4.2 4.6 4.7 5.1 5.5
24 hr 1.8 2.2 2.4 2.6 2.7 3.0 3.2
Table 5-4 - Historical IDF Table, St. John’s A Station, Precipitation intensities over the specified
duration, mm/hr
Return period (years)
2 5 10 20 25 50 100
5 min 56.2 77.0 90.8 104.0 108.2 121.1 133.9
10 min 41.6 55.7 65.0 74.0 76.8 85.6 94.2
15 min 34.9 46.9 54.8 62.4 64.9 72.3 79.7
30 min 24.9 32.8 38.0 43.0 44.6 49.5 54.4
1 hr 17.4 22.3 25.5 28.6 29.5 32.5 35.5
2 hr 11.9 15.8 18.4 20.9 21.7 24.1 26.5
6 hr 6.8 8.5 9.6 10.7 11.0 12.0 13.1
12 hr 4.4 5.3 5.9 6.5 6.7 7.3 7.9
24 hr 2.6 3.1 3.5 3.8 3.9 4.3 4.6
Table 5-5 - St. John’s Composite Record, Updated March 2012, Precipitation intensities over the
specified duration, mm/hr
Return period (years)
2 5 10 20 50 100
AMEC Environment & Infrastructure 31