Modelling the impact of sea-level rise on urban flood probability in SE China

Urban drainage systems in coastal cities in SE China are characterized by often complex canal and sluicegate systems that are designed to safely drain pluvial flooding whilst preventing tidal inundation.However, the risk of coastal flooding in the region is expected to increase over the next 50-100 years, as urban areas continue to expand and sea-levels are expected to rise. To assess the impact of projected sealevel rise on this type of urban drainage system, a one-dimensional model and decision support tool was developed. The model indicated that although sea-level rise represents a significant challenge, flood probability will continue to be most influenced by rainfall. Events that are significant enough to cause flooding will most likely be minimally impacted by changes to the tidal frame. However, it was found that a sea-level rise of up to 1.2 m by 2010 would result in increased drainage times and higher volumes of over-topping when flooding occurs.

The development of roadside green swales in the Chinese Sponge City Program:Challenges and opportunities

Roadside green swales have emerged as popular stormwater management infrastructure in urban areas,serving to mitigate stormwater pollution and reduce urban surface water discharge.However,there is a limited understanding of the various types,structures,and functions of swales,as well as the potential challenges they may face in the future.In recent years,China has witnessed a surge in the adoption of roadside green swales,especially as part of the prestigious Sponge City Program(SCP).These green swales play a crucial role in controlling stormwater pollution and conserving urban water resources by effectively removing runoff pollutants,including suspended solids,nitrogen,and phosphorus.This review critically examines recent research findings,identifies key knowledge gaps,and presents future recommendations for designing green swales for effective stormwater management,with a particular emphasis on ongoing major Chinese infrastructure projects.Despite the growing global interest in bioswales and their significance in urban development,China's current classification of such features lacks a clear definition or specific consideration of bioswales.Furthermore,policymakers have often underestimated the adverse environmental effects of road networks,as reflected in existing laws and planning documents.This review argues that the construction and maintenance of roadside green swales should be primarily based on three critical factors:Wellthought-out road planning,suitable construction conditions,and sustainable long-term funding.The integration of quantitative environmental standards into road planning is essential to effectively address the challenge of pollution from rainfall runoff.To combat pollution associated with roads,a comprehensive assessment of potential pollution loadings should be carried out,guiding the appropriate design and construction of green swales,with a particular focus on addressing the phenomenon of first flush.One of the major challenges faced in sustaining funds for ongoing maintenance after swale construction.To address this issue,the implementation of a green finance platform is proposed.Such a platform would help ensure the availability of funds for continuous maintenance,thus maximizing the long-term effectiveness of green swales in stormwater management.Ultimately,the findings of this review aim to assist municipal governments in enhancing and implementing future urban road designs and SCP developments,incorporating effective green swale strategies.

Urban agriculture as nature-based solutions:Three key strategies to tackle emerging issues on food security in Chinese cities under climatic and non-climatic challenges

1Introduction Achieving food and water security,according to the United Nations Sustainable Development Goals(SDGs),only requires a minimal environmental cost(Batalini de Macedo et al.,2022).However,in terms of agriculture,blindly devoting efforts to offset low-productivity farming or production techniques and industries,without systematic water,fertiliser,farm residue,tillage,and fallow management,will eventually interrupt the carbon sink under the soil and escalate greenhouse gas emissions,which is not helpful to meeting global climate targets.Thus,sciencebased land management practices are essential to decouple agricultural productivity from greenhouse gas emissions(Buscardo et al.,2021).