Assessing the performance of centralized blue-green infrastructure in dynamic stormwater storage and runoff assignment

Centralized blue-green infrastructure (CBGI) offers significant advantages for climate change adaptation due to substantial water storage, flexible drainage areas, and various social-ecological benefits. However, the planning and managing CBGI's dynamic storage and runoff assignment at a regional scale have not received adequate attentions. We propose to develop a scenario-based Stormwater Management Planning Support System for CBGI (SMPSS-CBGI) to calculate and assign runoff, as well as regulate contributing drainage area according to rainfall events and CBGI storage. This system has been implemented in an artificial lake in the Fengxi New City, Shaanxi, China. Twelve scenarios were developed according to rainfall intensities, management objectives, managing activities, and land use and climate changes. Runoff generation using the curve number method and CBGI storage simulation through terrain analysis were conducted in CommunityViz 5.2 integrated with ArcGIS. The findings indicated that CBGI successfully managed all runoff from 23 drainage units during a 10-year recurrence rainfall event. When the rainfall recurrence increased to a 50-year event, the number of drainage units effectively regulated by CBGI reduced to 10 out of 23. In future scenarios featuring extreme rainfall and a rise in impervious surfaces, CBGI regulated 25.7 % of the total runoff. It is advisable to integrate additional stormwater infrastructure to accommodate these anticipated changes. Meanwhile, SMPSS-CBGI can effectively incorporate stakeholder opinions and concerns through its user-friendly interface, which facilitates real-time updates and visualizations of results.