By Disaster Preparedness, Mitigation, and Management
4 June 2024: Dr. Indrajit Pal, Associate Professor and Chair of Disaster Preparedness, Mitigation and Management Program at AIT, recently co-authored a significant paper published in Nature Reviews Earth and Environment (IF 42.1), which sheds light on the urgent need for resilience planning in five of Asia’s mega deltas. The paper, titled “Building Resilience in Asian Mega-Deltas” explores the complex interplay of environmental and human-induced stressors affecting the Yangtze, Pearl, Ganga-Brahmaputra-Meghna (GBM), Mekong, and Chao Phraya deltas, which together house 80% of the global deltaic population and experience 90% of global flood exposure.
These regions, home to more than 400 million people, face a myriad of challenges, including flooding, tropical storms, storm surges, erosion, natural resource exploitation, and subsidence. Despite experiencing similar hazards, these deltas use different disaster management approaches due to variations in the stage of development and administrative and institutional contexts. “All deltas are developing and implementing certain short-term and long-term solutions to mitigate disaster risks and adapt to climate change. It is important for deltas to learn from one another about technological advances, innovative solutions, and risk management approaches to strengthen resilience building and foster regional collaboration,” explained Dr. Pal regarding the rationale behind the research conducted by a multi-disciplinary team of 15 researchers from China, the Netherlands, New Zealand, Singapore, Thailand, the United Kingdom, and Vietnam.
The paper illustrates the current and future challenges and risks faced by the deltas and discusses the different resilience-building approaches implemented to identify transferable solutions and lessons across the region. Most of these deltas are severely impacted by annual floods during their respective monsoon seasons, which bring in up to 90% of the annual rainfall between June and September. Similarly, the GBM, Yangtze, and Pearl deltas are also global hotspots for tropical storm activity, resulting in heavy winds, storm surges, and coastal inundation. The compound effect of fluvial, pluvial, and coastal flooding has a significant economic impact on the deltas. Moreover, the Pearl and Chao Phraya deltas are also threatened by increasing subsidence due to urban expansion and groundwater exploitation, which has increased their exposure to the effects of sea-level rise. Changes in geomorphology and hydrology due to salinization and disruption of sediment transport in the Mekong Delta have detrimental impacts on its people, 80% of whom are dependent on agriculture and fishing. Climate change, population growth, and urban expansion in the deltas are expected to escalate many of these challenges. Without proper management, these vibrant regions will be plunged into high disaster and climate-induced risks, and food and water insecurity, with severe impacts on the economy and society.
To combat these multifaceted threats, the deltas must engage in proactive resilience planning. Delta-wide initiatives like the Mekong Delta Plan, and Bangladesh Delta Plan 2100 provide essential frameworks for addressing these challenges. Technological advancements, such as improved disaster forecasting and monitoring systems, are enhancing anticipatory action and preparedness. Nature-based solutions such as Sponge Cities in Ninbo (China), Urban Wetland Parks in Bangkok (Thailand), and Mangrove Reforestation Programmes in Sundarbans (India) have helped increase local resilience, reducing the sole reliance on engineered coastal defenses that are expensive to construct and maintain. These are augmented by policies on resource management and community-level initiatives and adaptation projects, including neighborhood emergency support groups, small-scale flood protection (sandbags), diversification of livelihoods, and shared cropping.
To improve long-term resilience across all deltas, the paper recommends the integration of top-down approaches (such as engineered infrastructure, policies, and technological interventions) with bottom-up approaches (such as community adaptation projects, community groups, and capacity building). The authors also argue the need for sharing experiences and learnings, not just within different sectors within the delta but also across the deltas. For this, the authors recommend the formation of a regional delta alliance to facilitate knowledge, data, and information sharing amongst the deltas, encourage cross-collaboration, and stimulate innovation for sustainable delta management and resilience.
Read more here: https://doi.org/10.1038/s43017-024-00561-x
