VIET NAM: Slow Onset Hazard Interactions with Enhanced Drought and Flood Extremes in an At-Risk Mega-Delta
Lead Research Organisation:
University of Southampton
Department Name: Sch of Geography & Environmental Sci
Abstract
Layperson Summary (4000 characters max.)
The world's major river deltas are hotspots of agricultural production that support rural livelihoods and feed much of the global population, but as 'climate change hot spots' deltas are facing a major sustainability crisis. Specifically, there are concerns that many deltas may in the coming decades be 'drowned' by rising sea levels as the oceans warm (up to 20% of land is projected to be lost in the major deltas of south and southeast Asia alone). The process of delta 'drowning' is a slow onset hazard where relative sea-level rise progressively exacerbates fluvial and coastal flood risk while simultaneously enhancing saline intrusion. However, progressive environmental change is punctuated by the occurrence of extreme weather events such as droughts or extreme rainfall and climate models project that these will occur more frequently. The co-occurrence of slow onset hazards with extreme events creates a 'perfect storm' that makes agriculture ever more challenging, but we have almost no insight into how slow onset changes interact with extreme events. A key question is the extent (much like a boxer 'softening up' her opponent with repeated body blows before landing the knockout punch) to which, in systems facing progressive reductions in resilience as a result of ongoing change, the additional burdens caused by occasional but damaging climatic extremes may cause a 'tipping point' to be crossed which makes it difficult for agricultural production to recover after severe episodes of drought or flooding. This is a critical issue because if we cannot correctly attribute the cause of major change we run the risk that 'solutions' will also be applied incorrectly.
In this project we will develop a new model to examine how agricultural production and livelihoods are affected by combinations of progressive environmental change punctuated by extreme weather events. In particular we will focus on episodes of drought and flooding. Flooding is the most dangerous and costly of natural hazards, accounting for over 500,000 fatalities and economic losses of more than $1 trillion since 1980. Their low lying nature, alongside their location at the interface between coastal and fluvial environments means that deltas are disproportionately exposed to these risks. However, in the developing world, where agricultural production forms the mainstay of national economies and is central to livelihoods, drought can be a key driver of water and food (in)security, but we know significantly less about how droughts develop, persist and recover. We will further our understanding of the vulnerability of delta systems to extreme events by exploring how crop production and livelihoods are affected by the interplay between episodes of drought and flooding and ongoing environmental stress linked to upstream catchment management and climate change.
Our project is focused on the world's third largest delta, the Mekong. The Mekong delta is SE Asia's rice basket and home to almost 20 million people, but it is exposed to severe environmental risks as a result of climate change and rapid economic development. We will collaborate with our Vietnamese partners, including in key government agencies, to bring UK expertise in (i) the modelling of droughts and floods; (ii) agricultural livelihoods; (iii) participatory stakeholder engagement processes and (iv) social-ecological systems dynamics to bear on this challenge. We will define policy relevant scenarios of future change and quantify the links between drought and flooding and agricultural livelihoods, delivering an integrated assessment of the factors driving changes to livelihoods and explore the effects that adaptations could make to help make the Mekong delta more resilient to climatic extremes. This will be done within a globally significant, iconic, delta, providing a template for similar analyses in other vulnerable deltas of the Global South.
The world's major river deltas are hotspots of agricultural production that support rural livelihoods and feed much of the global population, but as 'climate change hot spots' deltas are facing a major sustainability crisis. Specifically, there are concerns that many deltas may in the coming decades be 'drowned' by rising sea levels as the oceans warm (up to 20% of land is projected to be lost in the major deltas of south and southeast Asia alone). The process of delta 'drowning' is a slow onset hazard where relative sea-level rise progressively exacerbates fluvial and coastal flood risk while simultaneously enhancing saline intrusion. However, progressive environmental change is punctuated by the occurrence of extreme weather events such as droughts or extreme rainfall and climate models project that these will occur more frequently. The co-occurrence of slow onset hazards with extreme events creates a 'perfect storm' that makes agriculture ever more challenging, but we have almost no insight into how slow onset changes interact with extreme events. A key question is the extent (much like a boxer 'softening up' her opponent with repeated body blows before landing the knockout punch) to which, in systems facing progressive reductions in resilience as a result of ongoing change, the additional burdens caused by occasional but damaging climatic extremes may cause a 'tipping point' to be crossed which makes it difficult for agricultural production to recover after severe episodes of drought or flooding. This is a critical issue because if we cannot correctly attribute the cause of major change we run the risk that 'solutions' will also be applied incorrectly.
In this project we will develop a new model to examine how agricultural production and livelihoods are affected by combinations of progressive environmental change punctuated by extreme weather events. In particular we will focus on episodes of drought and flooding. Flooding is the most dangerous and costly of natural hazards, accounting for over 500,000 fatalities and economic losses of more than $1 trillion since 1980. Their low lying nature, alongside their location at the interface between coastal and fluvial environments means that deltas are disproportionately exposed to these risks. However, in the developing world, where agricultural production forms the mainstay of national economies and is central to livelihoods, drought can be a key driver of water and food (in)security, but we know significantly less about how droughts develop, persist and recover. We will further our understanding of the vulnerability of delta systems to extreme events by exploring how crop production and livelihoods are affected by the interplay between episodes of drought and flooding and ongoing environmental stress linked to upstream catchment management and climate change.
Our project is focused on the world's third largest delta, the Mekong. The Mekong delta is SE Asia's rice basket and home to almost 20 million people, but it is exposed to severe environmental risks as a result of climate change and rapid economic development. We will collaborate with our Vietnamese partners, including in key government agencies, to bring UK expertise in (i) the modelling of droughts and floods; (ii) agricultural livelihoods; (iii) participatory stakeholder engagement processes and (iv) social-ecological systems dynamics to bear on this challenge. We will define policy relevant scenarios of future change and quantify the links between drought and flooding and agricultural livelihoods, delivering an integrated assessment of the factors driving changes to livelihoods and explore the effects that adaptations could make to help make the Mekong delta more resilient to climatic extremes. This will be done within a globally significant, iconic, delta, providing a template for similar analyses in other vulnerable deltas of the Global South.
Planned Impact
This proposal will bring together a range of experts with complementary expertise to address the challenge of understanding how environmental change impacts the sustainability of agriculture within a highly vulnerable mega-delta. We anticipate that this will benefit the following groups:
1. National and district actors in the water and agricultural sector. Our in-country partners (UNDP Viet Nam; Institute for Management of Agriculture and Rural Development, IMARD; Ministry of Natural Resources and Environment, MONRE; Center for Water Resources Warning and Forecasting, CEWAFO; Southern Institute for Water Resources Research, SIWRR; Can Tho University, CTU; Vietnam Japan University; Hanoi University of Natural Resources and Environment, HUNRE; Hanoi University of Civil Engineering, HUCE) will leverage their networks of contacts to invite representatives from key policy-making bodies, notably the Ministry of Natural Resources and Environment (MONRE), Ministry of Agriculture and Rural Development (MARD), and the Vietnamese National Environment Agency so that key stakeholders and policy makers attend and engage in our stakeholder workshops.
2. Affected communities / households: The Mekong delta is home to almost twenty million people. Their security in terms of space, water supply and political stability are conditional on the integrity of the delta in the next 100 years and beyond. We will engage with local community institutions and community members through the Key Informant Interviews conducted in the main research programme, giving a direct voice and participation in outcomes. Results will be fed-back directly to farmers through policy briefs (in Vietnamese) and participation workshops undertaken as part of our main work plan (see Case for Support).
3. Multilateral organisations and their bilateral counterparts/NGOs. Here we will engage primarily with our project partner (UNDP Viet Nam), who will offer the ability to further leverage access to ministries and act as an influential 'voice', while simultaneously providing a broader international perspective for other vulnerable deltas.
Our engagement with end-users is firmly embedded within the main work plan via a programme of stakeholder workshops that will be held regularly throughout core research programme. We will also produce a final policy brief (produced in collaboration with Southampton's dedicated knowledge transfer team, PublicPolicy@Southampton) which will summarise the main implications of our work within the Mekong delta. We will disseminate this policy brief (which will be published electronically and in hard form with versions in both English and Vietnamese) to the individuals/organisations identified by the stakeholder analysis phase.
Some of the benefits from the advances we will make in this project will be of value within the next 10 years whereas the impacts on health, economic growth, social cohesion and political stability extend over time-scales of decades to one hundred years, but these are the appropriate planning time horizons. Notably, the Mekong Delta Plan commissioned by the Vietnamese government provides a vision of a climate-resilient delta by 2100. Our work will contribute to this framework by providing specific advice on ways in which that vision could be realised. Finally, the UK will also benefit from improved forward planning and targeting of overseas aid to delta regions and provision of new technical solutions to sustainable delta management.
1. National and district actors in the water and agricultural sector. Our in-country partners (UNDP Viet Nam; Institute for Management of Agriculture and Rural Development, IMARD; Ministry of Natural Resources and Environment, MONRE; Center for Water Resources Warning and Forecasting, CEWAFO; Southern Institute for Water Resources Research, SIWRR; Can Tho University, CTU; Vietnam Japan University; Hanoi University of Natural Resources and Environment, HUNRE; Hanoi University of Civil Engineering, HUCE) will leverage their networks of contacts to invite representatives from key policy-making bodies, notably the Ministry of Natural Resources and Environment (MONRE), Ministry of Agriculture and Rural Development (MARD), and the Vietnamese National Environment Agency so that key stakeholders and policy makers attend and engage in our stakeholder workshops.
2. Affected communities / households: The Mekong delta is home to almost twenty million people. Their security in terms of space, water supply and political stability are conditional on the integrity of the delta in the next 100 years and beyond. We will engage with local community institutions and community members through the Key Informant Interviews conducted in the main research programme, giving a direct voice and participation in outcomes. Results will be fed-back directly to farmers through policy briefs (in Vietnamese) and participation workshops undertaken as part of our main work plan (see Case for Support).
3. Multilateral organisations and their bilateral counterparts/NGOs. Here we will engage primarily with our project partner (UNDP Viet Nam), who will offer the ability to further leverage access to ministries and act as an influential 'voice', while simultaneously providing a broader international perspective for other vulnerable deltas.
Our engagement with end-users is firmly embedded within the main work plan via a programme of stakeholder workshops that will be held regularly throughout core research programme. We will also produce a final policy brief (produced in collaboration with Southampton's dedicated knowledge transfer team, PublicPolicy@Southampton) which will summarise the main implications of our work within the Mekong delta. We will disseminate this policy brief (which will be published electronically and in hard form with versions in both English and Vietnamese) to the individuals/organisations identified by the stakeholder analysis phase.
Some of the benefits from the advances we will make in this project will be of value within the next 10 years whereas the impacts on health, economic growth, social cohesion and political stability extend over time-scales of decades to one hundred years, but these are the appropriate planning time horizons. Notably, the Mekong Delta Plan commissioned by the Vietnamese government provides a vision of a climate-resilient delta by 2100. Our work will contribute to this framework by providing specific advice on ways in which that vision could be realised. Finally, the UK will also benefit from improved forward planning and targeting of overseas aid to delta regions and provision of new technical solutions to sustainable delta management.
Organisations
- University of Southampton (Lead Research Organisation)
- National University of Civil Engineering (Project Partner)
- Institute of Management for Agriculture (Project Partner)
- Southern Inst of Water Resources Res (Project Partner)
- Center for Water Resources Warning & For (Project Partner)
- Vietnam Japan University (Project Partner)
- United Nations Development Programme (Project Partner)
- Hanoi Uni. of Natural Resources and Env. (Project Partner)
- Can Tho University (Project Partner)
- Ecole Francaise D'Extreme-Orient (Project Partner)
- NAWAPI (Project Partner)
Publications

Best J
(2020)
The Pace of Human-Induced Change in Large Rivers: Stresses, Resilience, and Vulnerability to Extreme Events.
in One earth (Cambridge, Mass.)


Bussi G
(2021)
Impact of dams and climate change on suspended sediment flux to the Mekong delta
in Science of The Total Environment

Du T
(2020)
Streamflow prediction in "geopolitically ungauged" basins using satellite observations and regionalization at subcontinental scale
in Journal of Hydrology

Du TLT
(2022)
Streamflow Prediction in Highly Regulated, Transboundary Watersheds Using Multi-Basin Modeling and Remote Sensing Imagery.
in Water resources research

Eslami S
(2021)
Projections of salt intrusion in a mega-delta under climatic and anthropogenic stressors
in Communications Earth & Environment

Eslami S
(2021)
Dynamics of salt intrusion in the Mekong Delta: results of field observations and integrated coastal-inland modelling
in Earth Surface Dynamics

