Urban Sediment Transport through an Established Vegetated Swale: Long Term Treatment Efficiencies and Deposition

Water

Deonie Allen¹  Valerie Olive²  Scott Arthur¹  Heather Haynes¹ 

[1] Institute of Infrastructure and Environment, Heriot-Watt University, Edinburgh EH144AS, UK; E-Mails:;Scottish Universities Environmental Research Centre, Rankine Avenue, East Kilbride G750QF, UK; E-Mail:

关键词: sustainable urban drainage;    vegetated swale;    rare earth tracing;    REO;    trapping efficiency;    detention;    urban pollution treatment;    impervious/vegetation boundary influence;    first order decay;    blue-green drainage network;   

DOI  :  10.3390/w7031046

来源: mdpi

【 摘 要 】

Vegetated swales are an accepted and commonly implemented sustainable urban drainage system in the built urban environment. Laboratory and field research has defined the effectiveness of a vegetated swale in sediment detention during a single rainfall-runoff event. Event mean concentrations of suspended and bed load sediment have been calculated using current best analytical practice, providing single runoff event specific sediment conveyance volumes through the swale. However, mass and volume of sediment build up within a swale over time is not yet well defined. This paper presents an effective field sediment tracing methodology and analysis that determines the quantity of sediment deposited within a swale during initial and successive runoff events. The use of the first order decay rate constant, k, as an effective pollutant treatment parameter is considered in detail. Through monitoring tagged sediment deposition within the swale, the quantity of sediment that is re-suspended, conveyed, re-deposited or transported out of the swale as a result of multiple runoff events is illustrated. Sediment is found to continue moving through the vegetated swale after initial deposition, with ongoing discharge resulting from resuspension and conveyance during subsequent runoff events. The majority of sediment initially deposited within a swale is not detained long term or throughout its design life of the swale.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.