Multiple ways to build urban resilience in coastal cities have been identified by researchers in Bangladesh, who say investment in sustainable urban drainage systems (SUDS) and green infrastructure, along with better governance and community engagement, all play a role.

Rapid urbanisation and climate change are intensifying urban flash floods and waterlogging, especially in coastal cities. In a new study published in Risk Sciences, researchers explore the growing challenges and offer practical solutions for building resilient and sustainable cities.

"In the face of accelerated urbanisation and the growing frequency of extreme weather events, cities across the Global South are increasingly vulnerable to flash floods and waterlogging," explains Abdullah Kaiser, assistant professor in public administration at the University of Chittagong.

"Chittagong, the second-largest city in Bangladesh, is emblematic of this crisis. Its coastal location, combined with rapid and often unplanned urban expansion, ageing infrastructure, poor drainage systems, and weak environmental governance, has made the city highly susceptible to seasonal urban flooding and water stagnation —disrupting lives, damaging infrastructure, and threatening long-term sustainability."

The study carries out 48 in-depth interviews with stakeholders from public, private, academic, and nonprofit sectors, along with field observations in key flood-prone zones.

"Rather than relying on simulations or big data models, our research draws on lived experiences and institutional insights to explore the multifaceted causes, impacts, and possible solutions to recurring urban water crises," adds Kaiser.

The key findings highlight the compounded role of governance failures, uncoordinated mega-projects, inadequate waste management, destruction of natural water bodies, and climate-induced pressures such as rising sea levels and intense monsoon rainfall. The impacts are wide-ranging — spanning economic loss, traffic paralysis, public health concerns, ecological degradation, and the displacement of vulnerable urban populations.

"Our findings emphasise the need for an integrated, multi-stakeholder approach to urban flood resilience. The stakeholders proposed concrete actions including the implementation of SUDS, improved zoning and land-use planning, investment in green infrastructure, stronger legal frameworks for environmental protection, and inclusive urban governance," says Kaiser.

"Emphasis was also placed on environmental education, community engagement, and aligning local policies with the Sustainable Development Goals (SDGs), particularly SDG 11 - Sustainable Cities and SDG 13 - Climate Action."

The researchers say their study contributes to the understanding of risk, resilience, and sustainability in coastal cities, offering actionable insights for policymakers, urban planners, and development agencies committed to transforming vulnerable urban areas into resilient, inclusive, and sustainable spaces.