Peng, Z. orcid.org/0000-0003-3918-4479, Smith, C. and Stovin, V. (2019) Internal fluctuations in green roof substrate moisture content during storm events: Monitored data and model simulations. Journal of Hydrology, 573. pp. 872-884. ISSN 0022-1694
Abstract
Understanding how the moisture content in a green roof substrate varies during a storm event is essential for accurately modelling runoff detention. In this paper, a green roof test bed installed with moisture probes at three depths was used to understand how moisture content varies during storms. Detailed studies were conducted on five selected storm events. Physical characterisation tests and field-data based calibrations were performed to acquire the model parameters. Two alternative detention models, based on Reservoir Routing and Richard’s Equation, were validated against the measured green roof runoff and temporary moisture storage data. Once the moisture content exceeds local field capacity, its response at different depths occurs simultaneously during storms, although the recorded data indicate a vertical gradient in the absolute values of local field capacity. Both Reservoir Routing and Richard’s Equation can provide reasonable estimations of the runoff and the vertical moisture content profiles, although Richard’s Equation exhibited stronger vertical water content gradients than were observed in practise. The vertical water content profile is not sensitive to the soil water release curve, although the hydraulic conductivity function influences both the vertical water content profile and runoff rate. The modelled results are highly sensitive to the bottom boundary condition, with a constant suction head boundary condition providing a more suitable option than a free drainage boundary condition or a seepage boundary condition.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Elsevier. This is an author produced version of a paper subsequently published in Journal of Hydrology. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
Keywords: | Green roof; Substrate; Detention modelling; Moisture content; Soil water release curve (SWRC); Hydraulic conductivity function (HCF) |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Civil and Structural Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 15 Apr 2019 11:46 |
Last Modified: | 03 Apr 2020 00:38 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.jhydrol.2019.04.008 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:144912 |