Rising Tides, Falling Harvests: Examining the Effects of Salinity Intrusion on Paddy Production in Vietnam's Mekong Delta

Abstract

Rising sea levels and salinity intrusion increasingly threaten rice farming in Vietnam's Mekong Delta. Using a district‐level panel dataset from 2000 to 2020, this study examines the impacts of salinity on Winter–Spring rice yields and acreage and how farmers adapt to salinity risk. A Nerlovian adaptive expectations model is applied to assess how past exposure influences land‐use decisions. Results show that extreme salinity events exert a stronger and more persistent effect on acreage adjustments than year‐to‐year fluctuations, with reductions most pronounced in salinity‐prone and coastal districts. Spatial heterogeneity underscores the need for location‐specific strategies: infrastructure and salt‐tolerant varieties for inland areas, and support for transitions to alternative land uses in highly exposed regions. Evidence of complementarities between rice and aquaculture suggests integrated systems can sustain production under moderate salinity pressure. These findings highlight the importance of tailored interventions to enhance resilience as salinity intrusion intensifies with sea‐level rise.