A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Influence of Biochar Amendment on Runoff Retention and Vegetation Cover for Extensive Green Roofs
Canadian cities broadly promote green roofs as a sustainable solution that mitigates urban flooding and combined sewage overflows. This study assessed the performance of eight extensive green roof testbeds for rainwater retention, discharge intensity, and vegetation growth in a highly urbanized area of Toronto, Canada, over a complete growing season (May–October 2021). The 3.24 m2 testbeds were constructed with high-organic substrate and two planting types: (1) a mix of native forbs and grasses planted from seed and (2) commercial Sedum spp. mats. The two vegetation treatments have very different establishment times and, thus, illustrated vegetation cover’s role in green roof hydrology. The substrate in four testbeds was amended with 5.4% (v/v) biochar made from pyrolysis of sugar-maple sawdust. Discharge from each testbed was measured with a 0.2 mm tipping bucket, and vegetation cover was assessed monthly using a three-dimensional pin-frame. Subject to 90 natural rain events, the green roof testbeds completely retained 87% and 40% of small (0.2–4.8 mm) and medium (5–19.8 mm) rain events, respectively. Testbeds with Sedum spp. had higher retention than those planted with native plant spp. likely due to higher vegetated coverage. Biochar had positive effects on water retention and peak discharge for testbeds with native plants for small events and the vegetation growth of these plant species.
Influence of Biochar Amendment on Runoff Retention and Vegetation Cover for Extensive Green Roofs
Canadian cities broadly promote green roofs as a sustainable solution that mitigates urban flooding and combined sewage overflows. This study assessed the performance of eight extensive green roof testbeds for rainwater retention, discharge intensity, and vegetation growth in a highly urbanized area of Toronto, Canada, over a complete growing season (May–October 2021). The 3.24 m2 testbeds were constructed with high-organic substrate and two planting types: (1) a mix of native forbs and grasses planted from seed and (2) commercial Sedum spp. mats. The two vegetation treatments have very different establishment times and, thus, illustrated vegetation cover’s role in green roof hydrology. The substrate in four testbeds was amended with 5.4% (v/v) biochar made from pyrolysis of sugar-maple sawdust. Discharge from each testbed was measured with a 0.2 mm tipping bucket, and vegetation cover was assessed monthly using a three-dimensional pin-frame. Subject to 90 natural rain events, the green roof testbeds completely retained 87% and 40% of small (0.2–4.8 mm) and medium (5–19.8 mm) rain events, respectively. Testbeds with Sedum spp. had higher retention than those planted with native plant spp. likely due to higher vegetated coverage. Biochar had positive effects on water retention and peak discharge for testbeds with native plants for small events and the vegetation growth of these plant species.
Influence of Biochar Amendment on Runoff Retention and Vegetation Cover for Extensive Green Roofs
Lecture Notes in Civil Engineering
Gupta, Rishi (editor) / Sun, Min (editor) / Brzev, Svetlana (editor) / Alam, M. Shahria (editor) / Ng, Kelvin Tsun Wai (editor) / Li, Jianbing (editor) / El Damatty, Ashraf (editor) / Lim, Clark (editor) / Saade, Jad (author) / Cazares, Samantha Pelayo (author)
Canadian Society of Civil Engineering Annual Conference ; 2022 ; Whistler, BC, BC, Canada
Proceedings of the Canadian Society of Civil Engineering Annual Conference 2022 ; Chapter: 71 ; 1117-1132
2023-08-17
16 pages
Article/Chapter (Book)
Electronic Resource
English
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