Adaptation to Sea Level Rise in the Vietnamese Mekong River Delta: Should a Sea Dike Be Built?

Abstract

Vietnam is one of the five countries in the world most likely to be seriously affected by climate change, most particularly from sea level rise (SLR). This study was conducted in Tra Vinh Province, which borders the Southeast Asia Sea and therefore represents an area of the Vietnam Mekong Delta (VMD) that would typically be affected by SLR. A risk cost-benefit analysis of the proposed construction of a concrete sea dike system to protect from SLR is conducted. The study develops five dike options associated with three hypotheses on the scale of different sea dike systems. Option 1 represents a dike that could withstand the severity of a storm that occurs once every 20 years. Options 2 and 3 represent a dike that could withstand the severity of a storm that occurs once every 50 years. Lastly, options 4 and 5 represent a dike that could withstand the severity of a storm that occurs once every 100 years. Based on the NPV decision rule, the results indicate that dike options should be recommended as an appropriate adaptation measure for the VMD, and the larger in scale the dike system options are, the higher are the ENPVs. The study recommends constructing a small dike system first, with the future option of increasing its height. The findings support the necessity of constructing a concrete sea dike system in the VMD given the context of global climate change.