Evaluating the reliability of stormwater treatment systems under various future climate conditions

JOURNAL OF HYDROLOGY

卷:568

Article

Zhang, Kefeng^1,2  Manuelpillai, Desmond¹  Raut, Bhupendra^3,4  Deletic, Ana^1,2  Bach, Peter M.^2,5,6 

[1] UNSW Sydney, Sch Civil & Environm Engn, Water Res Ctr, Sydney, NSW 2052, Australia

[2] Monash Univ, Dept Civil Engn, Monash Infrastruct Res Inst, Clayton, Vic 3800, Australia

[3] Monash Univ, Sch Earth Atmosphere & Environm, Melbourne, Vic, Australia

[4] Indian Inst Trop Meteorol, Pune, Maharashtra, India

[5] Swiss Fed Inst Aquat Sci & Technol Eawag, Uberlandstr 133, Dubendorf, Switzerland

[6] Swiss Fed Inst Technol, Inst Environm Engn, CH-8093 Zurich, Switzerland

关键词: General Circulation Model (GCM);    Climate downscaling;    Stormwater management;    Pollutant removal;    Stormwater harvesting;    Water Sensitive Urban Design (WSUD);   

DOI  :  10.1016/j.jhydrol.2018.10.056

来源: Elsevier

【 摘 要 】

Water Sensitive Urban Design (WSUD) stormwater systems, also known as Low Impact Development (LID) systems or Nature Based Solutions (NBS), are currently implemented based on the underlying assumption of statistical stationarity of rainfall, which threatens to become outdated under climatic uncertainty. This paper applies a new downscaling method to examine the implications of climate change on future rainfall and evaluate the reliability of WSUD stormwater infrastructure in pollution reduction, flow frequency mitigation and reliability as an alternative water supply. A variety of future atmospheric scenarios are considered as part of this comprehensive assessment by analysing an ensemble of eight different downscaled General Circulation Models (GCMs). High resolution catchment-scale rainfall projections for Melbourne, Australia were generated using a scheme called High-resolution Downscaling of Rainfall Using STEPS (HiDRUS) at a fine 1 km and 6-min scale for more precise analysis with uncertainty estimates. Statistical analyses show that, in general, the climate models predict a drier future with fewer rainfall events and longer dry periods when comparing the simulated near future (2040-2049) periods against the base-line period (1995-2004). The difference simulated between historical and future rainfall projections show minimum difference of WSUD performance in pollution removal and flow frequency reduction, with slightly lower harvesting reliability ( < 3%) observed under future climate; high variabilities, however, were observed across GCM simulations, indicating big uncertainties of system reliability under various conditions, e.g. design wetland sizes may vary from 2.5% to 4.0% of the impervious catchment area according to different future projects across GCMs. Larger WSUD systems are recommended to ensure reliable performance of pollution removal, as well as harvesting reliability under simulated future conditions. The significance of considering an ensemble of different GCMs as opposed to many scenarios generated by a single 'best' climate model was also demonstrated for the robust estimation of uncertainty in future WSUD reliability. This work highlights important considerations for the future design, management and quantitative evaluation of WSUD reliability.

【 授权许可】

Free