Hydraulic and environmental performance of green roofs in a continental Mediterranean dry climate. Application in a new urbanization of Zaragoza city (Spain)

Jimenez, A ; Russo, B ; Ruiz, O ; Acero, A

Resumen: Different hydroclimatology researchers apply eigenvectors-based techniques to compress large volumes of information while preserving the invariant structure of the original data. This research developed a methodology applying one of these techniques, Principal Component Analysis, on the elements of variability in hydroclimatic time series, and then to identify clusters with the k-means method. The result is a regionalized map by variable. Finally, these maps are intersected, obtaining areas with a homogeneous hydroclimatic structure, because the variables have similarity in their variance structure. In the case study, 8 variables were evaluated for Colombia (9268 time series), obtaining as a result 26 hydroclimatic regions. Obtaining hydroclimatically homogeneous regions The progressive increment of impervious areas in many of our cities contributes to the increase of surface runoff volumes that, moreover, reach the drainage network or, directly, the receiving water bodies without any type of filter provided by the vegetation. In this context, that in several sites could be exacerbated by the effects of climate change that are determining a drastic increase of maximum rainfall intensities, Sustainable Urban Drainage Systems (SUDS) suppose a valid alternative to address these kinds of problems, and providing, at the same time, a long series of other co-benefits at environmental and social level. The objective of this study is to propose the implementation of green roofs in a new urbanization of the city of Zaragoza and assess their hydraulic, environmental and socioeconomic benefits. The analysis of the hydraulic and environmental benefits has been performed through the USEPA-SWMM5 software that includes a specific module for SUDS simulations with special regard to green roofs, allowing to define and fully characterize their main layers and to simulate their effects at local or catchment scale. The hydrological simulations carried out for extreme rainfall events (return periods of 2, 5 and 10 years), indicate that the reduction of the hydrograph peaks can be between 31 y 38%, while the reduction in terms of runoff volumes is ranged from 17 up to 27 %. Concerning the simulation of a continuous annual rainfalls'' series, the reduction in runoff volumes would vary approximately between 30% and 37% depending on the type of green roof used. Finally, regarding the water quality parameters of the sewer discharged overflows, the reduction of pollutants would be very significant, varying from 92% to 99% depending on the type of pollutant and the type of roof.

Idioma: Español

DOI: 10.4995/Ia.2021.14112

Año: 2021

Publicado en: Ingeniería del agua 25, 2 (2021), 127-144
ISSN: 1134-2196

Tipo y forma: Artículo (Versión definitiva)