Catchment-scale life cycle impacts of green infrastructures and sensitivity to runoff coefficient with stormwater modelling

Sijie Tang; Xiao Yan; Jiping Jiang; Yi Zheng; Yang Yang; Peng Xu; Fangze Shang

doi:10.1016/j.scitotenv.2023.166736

Catchment-scale life cycle impacts of green infrastructures and sensitivity to runoff coefficient with stormwater modelling

Sci Total Environ. 2023 Dec 15:904:166736. doi: 10.1016/j.scitotenv.2023.166736. Epub 2023 Sep 1.

Authors

Sijie Tang¹, Xiao Yan², Jiping Jiang³, Yi Zheng², Yang Yang⁴, Peng Xu⁵, Fangze Shang⁶

Affiliations

¹ School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, 999077, Hong Kong, China.
² School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
³ School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China. Electronic address: jiangjp@sustech.edu.cn.
⁴ Shenzhen Howay Technology Co., Ltd, Shenzhen 518029, China; Peking University HSBC Business School, Shenzhen 518055, China.
⁵ State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
⁶ Power China Eco-environmental Group Co., Ltd, Shenzhen 518133, China.

PMID: 37659540
DOI: 10.1016/j.scitotenv.2023.166736

Abstract

Urban green infrastructure (GI) has been widely used in sponge city construction to manage hydrological processes. While studies on environmental benefits of GI from the perspective of whole life cycle assessment (LCA) have been reported in recent years, few have explored and compared the environmental performance of different GIs within a single catchment, which is directly linked to catchment-scale hydrological control. This study focuses on a Sponge City pilot project in Shenzhen, China, including three typical types of GI: permeable pavement, green roof, and sunken green space. By collecting hydrological data, land use, and life cycle inventory of GI and employing SWMM (Storm Water Management Model)-based stormwater modelling, we have revealed the environmental impacts at different stages of the life cycle of the GI scenario and three GIs through comparative and sensitivity analyses. Notably, we have disclosed, for the first time, the effect of the runoff coefficient in LCA. Our findings indicate that over the 30-year life cycle, the total environmental impact of the GI scenario is 24 % smaller than that of the hypothetical grey scenario. Permeable pavement exhibits the largest environmental impact per unit area, being 1.8 times and 7.6 times greater than that of the green roof and sunken green space, respectively. The operation stage of the three GIs significantly mitigates eutrophication and climate change. Furthermore, sensitivity analysis demonstrates that an increase in surface runoff undermines the environmental benefits of GIs. These results highlight the importance of embedding stormwater modelling into LCA, enabling catchment-scale integrated evaluation and equivalent assessment of different GIs within a single catchment whereby the influence of external factors such as climate change can be described, which aids in understanding the dynamic environmental performance of GIs. The proposed research framework and results are anticipated to provide valuable guidance for future GI construction and carbon-neutral policies.

Keywords: GaBi software; Green infrastructure; Life cycle assessment; SWMM; Sponge city.