An Interdisciplinary Approach to Understanding Past, Present and Future Flood Risk in Viet Nam

The impact of hydro-meteorological hazards is jointly determined by environmental and social factors. These interactions between environmental change and human responses generate great uncertainty when evaluating household vulnerability. In low-income countries, hydro-meteorological risks have been evolving due to climate change, changes in agricultural exploitation, changes in household mitigation strategies and waterway engineering activities related to hydropower and agriculture. In addition, flood risk itself affects the economic decisions of households in the short- and longer-run.

The proposed research will advance our understanding of how hydro-physical and socio-economic conditions and processes interact. Our novel, interdisciplinary approach will advance current knowledge and methods in both the physical and social sciences through the development of:

1) A technique for producing socio-physical flood models that account for interactions and feedback between social actors and physical systems;

2) A method for generating high-resolution social vulnerability maps based solely on remotely sensed data.

Within the context of Vietnam specifically our research will generate:

3) Detailed, multidimensional models of household-level risk and resilience strategies within communes in the Central Highlands;

4) High resolution maps of social vulnerability in the Central Highlands validated with household-level survey data;

5) A socio-physical flood risk model for the Central Highlands;

6) Scenario projections that outline potential future risks based on possible changes in key hydro-physical parameters, socioeconomic conditions, land use, household mitigation strategies, and public interventions.

Our geographical focus on the Central Highlands is informed by a clear dearth of recent research into flood risk in this area relative to other regions, such as the Mekong Delta and coastal areas in recent years, and by the major socio-economic changes affecting the region (rural-urban migration, changes in cropping patterns and investment, intensification of floodplain activity).

Our models, maps and scenarios for communities in the Central Highlands will be developed by integrating state-of-the-art hydrodynamic flood models, satellite imagery, detailed land-use maps, household survey data and field experiments. The results will improve our ability to predict and mitigate the impacts of hydrological hazards in the Central Highlands of Vietnam specifically, but also in other regions affected by similar hazards. To our knowledge, our proposal is the first one to combine a state-of-the-art hydrodynamic flood model with data on resilience strategies and economic activities that is geo-located at the household level anywhere in the world. This contribution will allow us to incorporate household resilience when projecting future scenarios and thus make a significant contribution to policy-relevant knowledge, while also providing new modelling methods that could be applied in other regions.

The project aims to deepen our understanding of socio-economic vulnerability to hydro-meteorological hazards in the Central Highlands, Vietnam. The project addresses a question that is central in Vietnam and other low-income economies of South-East Asia: it proposes to quantify the impact of flood exposure on welfare, accounting for the nature of economic activities, and the existence of risk-mitigating instruments and post-disaster support. Three aspects of the proposed research are crucial to maximise potential impact. First, the project will generate state-of-the-art socio-economic flood hazard maps at a high resolution, for the Central Highlands but using a method that could be applied across Vietnam as a whole. Second, the project will consider a wide range of projections incorporating climate change and trends in land use and households resilience strategies. Third, the project will incorporate a detailed analysis of households resilience strategies and provide a welfare analysis based on a theoretical model. This quantitative approach thus allows to evaluate the household response to a wide range of environmental policies.

The proposed research will assemble a high-resolution hydrodynamic model, unique geo-referenced household data and satellite imagery to produce socio-economic flood hazard maps. The produced data will be useful for natural disaster prevention and control activities. As the research output will integrate flood exposure, economic activity at risk, and household strategic response. The project will provide a quantitative framework whose role is to provide (i) a better understanding of household resilience strategies, (ii) a welfare analysis (a quantification of vulnerability to flood exposure) and (iii) a set of policy evaluations for environmental policies, focusing on their possible heterogeneous effects across households. The following environmental and urban policies could be evaluated (based on Viet Nam: Law on natural disaster prevention and control, 2013): (P1) targeted-subsidies for agricultural activities in high-risk areas, (P2) resource mobilisation to invest in commune-level infrastructure (irrigation, natural disaster funds), (P3) development of specific insurance products. The final set of policy scenarios will be elaborated after a meeting with key stakeholders (see below).

Relevant users of research: The research will be useful to policymaking institutions in Vietnam and other low-income economies of South-East Asia. We have identified the following institutions in Vietnam as key end users: the Institute of Strategy and Policy on Natural Resources and Environment (ISPONRE), which belongs to the Ministry of Natural Resources and Environment (MONRE); the Department of Water Resources Management (DWRM), also part of the Ministry of Natural Resources and Environment; the Provincial Peoples Committee of Dak Lak; the Provincial Peoples Committee of Lam Dong; the Central Committee for Natural Disaster Prevention and Control (CCNDPC); the Vietnam Red Cross.

For dissemination activities, we will first and foremost rely on the existing network of Dr Nam and Dr Thuy, in particular the Economy and Environment Program for Southeast Asia (EEPSEA). Through its publications and the organisation of specific events for government policymakers and other end users, the EEPSEA, led by lead Dr Nam, is the most important research dissemination network for environmental economics in South-East Asia.