Modelling of green roof hydrological performance for urban drainage applications

Luca Locatelli; Ole Mark; Peter Steen  Mikkelsen; Karsten Arnbjerg-Nielsen; Marina Bergen Jensen; Philip John  Binning

doi:10.1016/j.jhydrol.2014.10.030

Modelling of green roof hydrological performance for urban drainage applications

Luca Locatelli, Ole Mark, Peter Steen Mikkelsen, Karsten Arnbjerg-Nielsen, Marina Bergen Jensen, Philip John Binning

Landscape Architecture and Planning

77 Citations (Scopus)

Abstract

Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes surface and subsurface storage components representing the overall retention capacity of the green roof which is continuously re-established by evapotranspiration. The runoff from the model is described through a non-linear reservoir approach. The model was calibrated and validated using measurement data from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010–2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989–2010) continuous simulation with Danish climate data. The results show that during single events, the 10 min runoff intensities were reduced by 10–36% for 5–10 years return period and 40–78% for 0.1–1 year return period; the runoff volumes were reduced by 2–5% for 5–10 years return period and 18–28% for 0.1–1 year return period. Annual runoff volumes were estimated to be 43–68% of the total precipitation. The peak time delay was found to greatly vary from 0 to more than 40 min depending on the type of event, and a general decrease in the time delay was observed for increasing rainfall intensities. Furthermore, the model was used to evaluate the variation of the average annual runoff from green roofs as a function of the total available storage and vegetation type. The results show that even a few millimeters of storage can reduce the mean annual runoff by up to 20% when compared to a traditional roof and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans.

Original language	English
Journal	Journal of Hydrology
Volume	519
Pages (from-to)	237–3248
ISSN	0022-1694
DOIs	https://doi.org/10.1016/j.jhydrol.2014.10.030
Publication status	Published - 27 Nov 2014

Access to Document

10.1016/j.jhydrol.2014.10.030

Cite this

@article{b4b8aeb64c8740f38113d015ab223708,

title = "Modelling of green roof hydrological performance for urban drainage applications",

abstract = "Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes surface and subsurface storage components representing the overall retention capacity of the green roof which is continuously re-established by evapotranspiration. The runoff from the model is described through a non-linear reservoir approach. The model was calibrated and validated using measurement data from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010–2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989–2010) continuous simulation with Danish climate data. The results show that during single events, the 10 min runoff intensities were reduced by 10–36% for 5–10 years return period and 40–78% for 0.1–1 year return period; the runoff volumes were reduced by 2–5% for 5–10 years return period and 18–28% for 0.1–1 year return period. Annual runoff volumes were estimated to be 43–68% of the total precipitation. The peak time delay was found to greatly vary from 0 to more than 40 min depending on the type of event, and a general decrease in the time delay was observed for increasing rainfall intensities. Furthermore, the model was used to evaluate the variation of the average annual runoff from green roofs as a function of the total available storage and vegetation type. The results show that even a few millimeters of storage can reduce the mean annual runoff by up to 20% when compared to a traditional roof and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans.",

author = "Luca Locatelli and Ole Mark and Mikkelsen, {Peter Steen} and Karsten Arnbjerg-Nielsen and Jensen, {Marina Bergen} and Binning, {Philip John}",

year = "2014",

month = nov,

day = "27",

doi = "10.1016/j.jhydrol.2014.10.030",

language = "English",

volume = "519",

pages = "237–3248",

journal = "Journal of Hydrology",

issn = "0022-1694",

publisher = "Elsevier",

}

TY - JOUR

T1 - Modelling of green roof hydrological performance for urban drainage applications

AU - Locatelli, Luca

AU - Mark, Ole

AU - Mikkelsen, Peter Steen

AU - Arnbjerg-Nielsen, Karsten

AU - Jensen, Marina Bergen

AU - Binning, Philip John

PY - 2014/11/27

Y1 - 2014/11/27

N2 - Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes surface and subsurface storage components representing the overall retention capacity of the green roof which is continuously re-established by evapotranspiration. The runoff from the model is described through a non-linear reservoir approach. The model was calibrated and validated using measurement data from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010–2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989–2010) continuous simulation with Danish climate data. The results show that during single events, the 10 min runoff intensities were reduced by 10–36% for 5–10 years return period and 40–78% for 0.1–1 year return period; the runoff volumes were reduced by 2–5% for 5–10 years return period and 18–28% for 0.1–1 year return period. Annual runoff volumes were estimated to be 43–68% of the total precipitation. The peak time delay was found to greatly vary from 0 to more than 40 min depending on the type of event, and a general decrease in the time delay was observed for increasing rainfall intensities. Furthermore, the model was used to evaluate the variation of the average annual runoff from green roofs as a function of the total available storage and vegetation type. The results show that even a few millimeters of storage can reduce the mean annual runoff by up to 20% when compared to a traditional roof and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans.

AB - Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes surface and subsurface storage components representing the overall retention capacity of the green roof which is continuously re-established by evapotranspiration. The runoff from the model is described through a non-linear reservoir approach. The model was calibrated and validated using measurement data from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010–2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989–2010) continuous simulation with Danish climate data. The results show that during single events, the 10 min runoff intensities were reduced by 10–36% for 5–10 years return period and 40–78% for 0.1–1 year return period; the runoff volumes were reduced by 2–5% for 5–10 years return period and 18–28% for 0.1–1 year return period. Annual runoff volumes were estimated to be 43–68% of the total precipitation. The peak time delay was found to greatly vary from 0 to more than 40 min depending on the type of event, and a general decrease in the time delay was observed for increasing rainfall intensities. Furthermore, the model was used to evaluate the variation of the average annual runoff from green roofs as a function of the total available storage and vegetation type. The results show that even a few millimeters of storage can reduce the mean annual runoff by up to 20% when compared to a traditional roof and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans.

U2 - 10.1016/j.jhydrol.2014.10.030

DO - 10.1016/j.jhydrol.2014.10.030

M3 - Journal article

SN - 0022-1694

VL - 519

SP - 237

EP - 3248

JO - Journal of Hydrology

JF - Journal of Hydrology

ER -