Can flood resilience of green-grey-blue system cope with future uncertainty?

Urban flooding is becoming a great global concern due to growing cities, while climate change and urbanization may pose daunting challenges to both environment and humans. The integrated green-grey-blue (IGGB) system has gained interests worldwide to mitigate flood issues, however, how IGGB system acts in urban flood resilience and whether it can address future uncertainties have not been fully understood. In this study, a new framework, which combined an evaluation index system and coupling model, was constructed to quantify urban flood resilience (FR) and its responses to future uncertainties.

Comprehensive modelling and cost-benefit optimization for joint regulation of algae in urban water system.

Algal blooms in urban water system is an international concern, which especially in China, have become a major obstacle to the urban water environment improvement since the preliminary achievements were made in the treatment of black and odorous water bodies. The complex blooming mechanisms require a joint regulation plan. This study established a framework that consisted of three steps, i.

Environmental and economic cost-benefit comparison of sponge city construction in different urban functional regions.

This study conducts a life cycle environmental and economic quantification comparison of urban runoff source control facilities (URSCFs) through construction and operation stages in two urban functional regions (i.e., residential area and campus).

An interval chance-constrained programming-based optimization model for carbon capture, utilization, and storage system planning.

Carbon capture, utilization, and storage (CCUS) are widely regarded as a crucial technological option for industrial large-scale carbon dioxide (CO) emissions reduction. However, high-cost and uncertainties hinder the widespread application of CCUS technology. In this study, an interval-chance-constrained programming-based optimization model was proposed to address random probability distributions, interval values, complex interactions, and the dynamics of capacity expansion issues.

Multi-factor analysis of algal blooms in gate-controlled urban water bodies by data mining.

Intense human disturbance has made algal bloom a prominent environmental problem in gate-controlled urban water bodies. Urban water bodies present the characteristics of natural rivers and lakes simultaneously, whose algal blooms may manifest multi-factor interactions. Hence, effective regulation strategies require a multi-factor analysis to understand local blooming mechanisms.

Performance assessment of coupled green-grey-blue systems for Sponge City construction.

In recent years, Sponge City has gained significant interests as a way of urban water management. The kernel of Sponge City is to develop a coupled green-grey-blue system which consists of green infrastructure at the source, grey infrastructure (i.e.

Factors affecting the ability of extensive green roofs to reduce nutrient pollutants in rainfall runoff.

Green roofs can retain urban rainfall runoff, but there are doubts about whether they can reduce urban nonpoint source pollution. To explore the factors affecting the ability of green roofs to reduce nutrients in rainfall runoff, nine types of extensive green roofs (EGRs) were analysed during 38 natural rainfall events and two early spring irrigation runoff events from 1 March to 30 November 2019 in Beijing. Differences among the module scale, growing medium material, growing medium depth, drainage layer material, planting time, rainfall characteristics and seasonal variation were examined to study their correlation with pollutant event mean concentration (EMC) and the load reduction performance of EGRs.

Integrated 1D and 2D model for better assessing runoff quantity control of low impact development facilities on community scale.

This study proposes a modelling framework of integrated one-dimensional (1D) and two-dimensional (2D) hydrodynamic modelling to evaluate the effectiveness of sponge city construction at community scale. Through a case study in Zhuhai, we integrate Stormwater Management Model (SWMM) and Cellular Automata Dual-DraInagE Simulation (CADDIES) 2D model to analyze the rainfall-runoff process involving green infrastructures. SWMM is applied to analyze the change of surface runoff control effects before and after the implementation of sponge city low impact development (LID) facilities, and CADDIES is adopted to simulate the propagation of excess runoff on the surface.

Performance assessment of extensive green roof runoff flow and quality control capacity based on pilot experiments.

Green roof is an important measure in "Sponge Cities" to reduce the runoff and improve the runoff quality. The runoff quantity and quality control capacity of five types of extensive green roofs (EGRs) were analyzed in Beijing for 51 nature rainfall events and 6 simulated events from July 2017 to October 2018. Different module scales (sizes) and substrate depths were examined to study their correlation to runoff retention, peak flow reduction, pollutant event mean concentration (EMC) and load reduction performance of EGRs.