The software RECARGA is used to model the water content of bioretention cells by comparing two rates of hydraulic conductivity (0,5 cm/hr and 5,7 cm/hr) and the impact on tree growth. 3 cells built in a parking lot were monitered from August 2009 to August 2010 to observe the development of the trees planted. The availability of water in the soil at root level varies depending on rainfall and soil moisture contributes to the ability of plant photosynthesis and thus its development. The hydraulic conductivity of the planting soil and its depth are key factors for plant survival in these systems. The amount of wilting events increases and lasts longer with a substrate of higher hydraulic conductivity. Inversly, when the conductivity is lower, the lengths of floods and events of overflows will increase. The modeling results indicate that cells can retain on site 45 to 97% of rainwater by soil evaporation and soil recharge. In addition, an interception calculation for Quercus rubra, Quercus bicolor and Acer rubrum shows that each tree can intercept 2,1 m3 to 12,9 m3 of rain for the periods identified, representing 1,6 to 8% of the annual . The volume intercepted is more important in a year with a majority of smaller events. Mature trees could reduce the total amount of rainwater directed into the bioretention cells, decreasing the water available to other plants and increasing wilting events of potential loss of plants.
| Date | 21 Dec 2010 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Robert Hausler (Supervisor) & Daniel Forgues (Co-supervisor) |
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Glorieux, M. (Author),
Hausler (Supervisor) &
Forgues (Co-supervisor),
21 Dec 2010Student thesis: Master's thesis › Master in Engineering: Engineering