The DHI technical team, supported by UNEP-DHI colleagues, is working together with the Viet Nam Mekong Committee (VNMC) to develop a salinity data sharing platform to enable exchange of information and near-real-time data on salinity intrusion in the Viet Nam Mekong Delta region. This project is funded by the Climate Technology Centre and Network (CTCN).

A delta under pressure

Viet Nam’s Mekong Delta, the world’s third largest delta, is home to around 17 million people whose livelihoods depend largely on agriculture and aquaculture. With an average elevation of only ~80 cm above sea level, the delta is extremely vulnerable to sea-level rise and climate change impacts, including more frequent and intense dry seasons, droughts, and saline intrusion. These impacts are already evident, with saltwater encroaching further inland and causing significant environmental, economic, and social damage.

Saltwater intrusion – damaging crops and cutting off freshwater

Saltwater damages rice, fruit trees, and other crops, and reduces yields or causes complete crop failure during severe intrusion years. When rivers and canals turn brackish, communities also lose access to safe water for drinking, cooking, and daily use.

During the 2019 – 2020 dry season, saltwater intrusion affected 10 out of 13 provinces in the Mekong Delta. Salinity persisted for nearly six months and reached up to 125 km inland, more than 30 km beyond long‑term average intrusion levels. In recent dry seasons, tens of thousands of people across the Viet Nam Mekong Delta have faced freshwater shortages, while large areas of agricultural land have experienced significant crop damage or failure. Evidence increasingly shows that dry seasons in the Mekong Delta are arriving earlier, lasting longer, and becoming less predictable, placing growing pressure on livelihoods across the region.

Salinity data is available, but not connected

National and provincial institutions in Viet Nam can reduce the impacts of salinity intrusion through better monitoring, forecasting, and early warning. Timely access to salinity information allows more proactive management of freshwater during the dry season and supports action on key drivers, such as groundwater over‑extraction. It also provides critical information to farmers and communities to adapt, for example through crop diversification, water storage, and targeted livelihood support.

However, despite significant investments in salinity monitoring infrastructure across the Delta, data remains fragmented across multiple institutions. Financial and technical constraints limit coordination and effective use of existing monitoring stations. As a result, actionable information is often not available in time to support decision‑making or coordinated responses to salinity risks.

Building a shared system for salinity data

Recognizing these challenges, the Viet Nam National Mekong Committee requested technical assistance support from CTCN to strengthen the salinity intrusion data sharing and forecasting capabilities.

The project implementation is led by DHI, with support from the UNEP-DHI Centre, and will focus on building the salinity monitoring and forecasting capabilities by:

1. Developing a salinity data sharing platform to collect, manage, and share salinity information in one place
2. Strengthening salinity modelling and near real‑time forecasting capabilities using DHI’s MIKE+ tools
3. Developing tools to generate high‑resolution salinity intrusion maps to support decision‑making
4. Building capacity of VNMC staff and other system users to operate the system and use its outputs effectively.