The main purpose of this study is to develop a physical method to assess a summer PMP probable maximum precipitation), under recent climate and transposable under a projected climate. This method is based on the moisture maximisation method developped by WMO (World Meteorological Organization). Precipitable water amounts are evaluated using specific and relative humidity output data from CRCM (Canadian Regional Climate Model). Studied past and projected climates (1961-2000 and 2011-2100) have different durations, 40 and 90 years, respectively. Comparing results show the PMP intensity will increase. An intensification in rainfall and increase in potential humidity amounts explain this result.
This new PMP value is used to asses a PMF (probable maximum flood) under climate change conditions. Floods resulting from hydrological modelisation show discrepancies. These are PMP intensity, spatial distribution, upscaling at watershed scale and initial conditions prevalent. Two factors may explain 3% gap over PMF result : 5 mm over PMP intensity, at tile scale, or reduction factor less than 3% smaller. Under a projected climate, soil humidity variation is significative, yet may explain approximately 0,3% of the PMF result variation. Half PMP occuring before PMP event is a common practice. According to 95% confidence level, this practice may overestimate PMF value by 13%.
Under a future climate, analysis of present results show an increase of 28% for the 72 hours PMP, over Manic5 watershed, and in regard of CRCM data. This increase and greater soil humidity conditions induces an increase of 27% over the PMF value for the same watershed.
| Date | 16 Sept 2010 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Robert Leconte (Supervisor) & François Brissette (Co-supervisor) |
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Beauchamp, J. (Author), Leconte (Supervisor) &
Brissette (Co-supervisor),
16 Sept 2010Student thesis: Master's thesis › Master in Engineering: Construction Engineering