Adaptation strategies in deltas and their consequence on maritime baselines according to UNCLOS –the case of Bangladesh and Vietnam

• Sea level rise may flood deltas if no adaptation countermeasures are adopted.
• Baselines in deltaic areas change when the coastal State resurveys the baselines.
• Delta states should consider adaptation strategies against climate change.

The Mekong delta in Vietnam and the Ganges/Brahmaputra River delta in Bangladesh are likely to be two of the deltas worst affected by climate change in the course of the 21st century. Due to sea level rise, and if significant adaptation measures are not taken, large areas of these low-lying coastlines could eventually become submerged. This paper will explore some of the consequences that climate change and sea level rise can have on maritime baselines and deltaic areas, according to publicized charts by the States involved and to the United Nations Convention on the Law of the Sea (UNCLOS). The study will argue that although great changes are likely to take place at the geographical level, due to the complex geomorphological nature of deltas and how they will be affected by sea level rise, these will not necessarily translate into changes in maritime baselines and the classification of these areas according to UNCLOS. Furthermore, other forms of adaptation to sea level rise, such as the construction of coastal defences, could turn the Mekong and Ganges/Brahmaputra River deltas into “polders”, with similar characteristics and problems as the Netherlands nowadays.