Detention and Retention Behavior of Four Extensive Green Roofs in Three Nordic Climate Zones

Johannessen, Birgitte Gisvold; Muthanna, Tone Merete; Braskerud, B.C.

doi:10.3390/w10060671

Cited by 55 publications

(53 citation statements)

References 50 publications

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“…The initial saturation in the green roof model is important as it defines the available retention capacity when precipitation starts, and was set to 5 mm. This is an approximate conservative value based on observations in Bergen, Sandnes, Trondheim and Oslo [50], as can also be seen when compared to the results from the green roof water balance model. The SWMM green roof module and a comparative black bitumen reference roof were based on parameters derived from a multi-site calibration of the model with field data [60].…”

Section: Design Event Modelssupporting

confidence: 56%

“…The green roofs modelled in this study were based on a build-up used in field studies in four Norwegian sites; Trondheim, Bergen, Sandnes and Oslo [50]. The field studies had a build-up consisting of a 30 mm pre-grown, sedum-based vegetation mat over additional 50 mm of green roof substrate, a 25-75 mm plastic or polystyrene drainage layer and a 5 mm thick textile retention fabric as the bottommost layer.…”

Section: Low-impact Development (Lid) Performance Assessmentmentioning

confidence: 99%

“…The model applied in [34] was improved by calibrating the crop coefficient based on three years of continuous observations from field studies [50]. The model was calibrated was based on minimizing the objective function relative percentage difference (RPD) for three year of continuous data (2015-2017) and validated with the objective function Nash-Sutcliffe efficiency (NSE) for non-winter data [58].…”

Section: Daily Time-step Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Temporal Downscaling of IDF Curves Applied to Future Performance of Local Stormwater Measures

Kristvik¹,

Johannessen²,

Muthanna³

2019

Sustainability

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Low-impact development (LID) structures are combined with traditional measures to manage stormwater and cope with increased runoff rates originating from heavy urbanization and climate change. As the use of LIDs for climate adaptation increases, practitioners need more knowledge on LID performance in future climates for successful planning and implementation. In this study, temporal downscaling of regional climate projections for three cities in Norway is performed, using the concept of scale invariance to downscale the distribution of extreme precipitation from daily to sub-daily timescales. From this, local-scale intensity-duration-frequency (IDF) curves for future precipitation were obtained. Using climate projections of daily temporal resolution as input to water balance models and the obtained IDF relationships as input to event-based models allowed for assessing the retention capacity, peak flow reduction potential and pollution control of three different types of LIDs: green roofs, bioretention cells, and detention basins. The downscaling resulted in large local variations in presumed increase of both precipitation amount and intensity, contradicting current design recommendations in Norway. Countrywide, a decrease in the overall LID performance was found, although some positive effects of temperature rises were detected. The study illustrated the importance of evapotranspiration- and infiltration-based processes in future stormwater management and how coupling of LID structures in series can significantly reduce required detention volumes.

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Section: Design Event Modelssupporting

confidence: 56%

Section: Low-impact Development (Lid) Performance Assessmentmentioning

confidence: 99%

Section: Daily Time-step Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Temporal Downscaling of IDF Curves Applied to Future Performance of Local Stormwater Measures

Kristvik¹,

Johannessen²,

Muthanna³

2019

Sustainability

Self Cite

View full text Add to dashboard Cite

show abstract

“…Green roofs, also referred to as vegetated roofs and ecoroofs are layered roofs covered with vegetation and growing medium [12,13]. Green roofs can be typically divided into three main categories: intensive, simple intensive (semi-intensive), and extensive green roofs [13,14].…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Influence of Hydrogel Amendment on the Retention Capacities of Green Roofs

Deska

Mrowieć

Ociepa

et al. 2018

Ecological Chemistry and Engineering S

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Progressive economic development as well as urbanisation influence the characteristics of the stormwater runoff. Progressive sealing of drainage basin surface prompts the decrease of rainwater infiltration, thus increasing the runoff intensity. This results in an increase of flood risk. Thus, in urban areas the sustainable urban drainage systems (SUDS) are used in addition to the traditional sewer systems. The examples of SUDS strategy are, inter alia, the roofs covered with vegetation (the green roofs). The paper presents the results of research of retention capacities of 4 diverse green roof models with following growing media: (1) the typical green roof substrate without any additions, (2) the substrate with addition of about 1 % by weight of hydrogel (the cross-linked potassium polyacrylate), (3) the substrate with addition of about 0.25 % by weight of hydrogel, (4) the substrate with addition of expanded clay and perlite. The models did not have the vegetation layers in order to explore only the retention capacities of drainage layers and substrates. The aim of the first part of research was to investigate the retention capacities of green roof models after 1, 2, 6, 8 and 10 antecedent dry days. In the case of 1 and 2 antecedent dry days the best medium retention capacity had green roof model 2 (with substrate with addition of 1 % by weight of hydrogel), and the weakest medium retention capacity had green roof model 1 (without any additions). In the cases of precipitations which occurred after 6 as well as 8 and 10 antecedent dry days the best retention capacity had green roof model 3 (with addition of about 0.25 % by weight of hydrogel). The weakest retention capacity had in these cases green roof model 4 (with addition of expanded clay and perlite). The aim of the second part of research described in the paper was to investigate the retention capacities of green roof models during precipitations that occurred after long antecedent dry periods of time (34, 59 and 106 antecedent dry days). The substrates and drainage layers were air-dry directly before precipitations. The best retention capacity had in this case green roof model 3 (with the substrate with addition of about 0.25 % by weight of hydrogel). The second largest retention capacity had model 2 (with the substrate with addition of about 1 % by weight of hydrogel). The definitely weakest retention capacity had model 4 containing the substrate with addition of expanded clay and perlite. The results may indicate that the efficacy of hydrogel decreased over time probably due to its decay under the influence of solar radiation.

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“…Previous research on this topic is primarily experimental and covers laboratory scale experiments through full-scale green roofs. A heavily important factor in the performance of green roofs is evapotranspiration as outlined in [4,5] due to the nature of liquid storage in porous soil substrates.…”

Section: Introductionmentioning

confidence: 99%

On the impact of porous media microstructure on rainfall infiltration of thin homogeneous green roof growth substrates

Pettersson

Maggiolo

Sasic

et al. 2020

Journal of Hydrology

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Green roofs are considered an attractive alternative to standard storm water management methods; however one of the primary issues hindering their proliferation is the lack of data regarding their ability to retain and reduce storm water under a variety of climatic conditions. This lack of data is partly due to the complexity of physical processes involved, namely the heterogeneous microscopic behavior that characterize flows in unsaturated porous media.

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Detention and Retention Behavior of Four Extensive Green Roofs in Three Nordic Climate Zones

Cited by 55 publications

References 50 publications

Temporal Downscaling of IDF Curves Applied to Future Performance of Local Stormwater Measures

Temporal Downscaling of IDF Curves Applied to Future Performance of Local Stormwater Measures

Investigation of the Influence of Hydrogel Amendment on the Retention Capacities of Green Roofs

On the impact of porous media microstructure on rainfall infiltration of thin homogeneous green roof growth substrates

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