Monitoring Increasing Salinity of the Mekong Delta

Written by Jessica Morgan, based on paper by Guido Rutten

IFAD has initiated a programme to develop a monitoring and early warning system to combat the increasing salinity levels of the Mekong Delta.

The Mekong Future Project - First draft report on the
hydrological simulation.
To Quang Toan, Nguyen Hieu Trung, Dang Kieu Nhan.
At the mouth of the Mekong, salty seawater rushes inland to mingle with the fresh water. This balance between fresh and saltwater is crucial to the ecosystems that inhabit the area, however with increasing water extraction of freshwater upstream and rising sea levels downstream the careful balance is tipping. Saltwater is now moving further up the Mekong estuary with devastating effects.
Natural ecosystems and human activities are dependent on the salinity balance within the delta. As freshwater is becoming scarce, management of the delta system is focused on protecting freshwater sources through heavy infrastructure. However, this is largely unsustainable and IFAD is attempting to move to an adaptation strategy. Examples include adjusting cropping calendars and introducing saline tolerant rice.

However, the basis for creating a successful adaptation system is reliable knowledge. Farmers need access to accurate information systems to determine when the water will be at its most saline or at its freshest. Also people, such as irrigation system managers, need to know when to open and close floodgates and where and when new infrastructure investments are required. This knowledge is essential to accommodate adaptation needs.

However to put this into practice is quite a challenge. Monitoring salinity is not an easy task in an estuary. The Mekong Delta consists of a variety of different rivers, irrigation systems, drainage canals, dikes and floodgates. Consequently water flow is varied resulting in a patchy distribution of salinity levels. The tidal nature of the delta also increases high variation in readings making interpretation of data extremely difficult.

To make matters worse, there is currently no shared base of knowledge for the various stakeholders. This can lead to a lack of knowledge among  people such as smallholder farmers, who usually are the individuals most affected by the increasing salinity.

The Adaptation in the Mekong Delta (AMD) project will develop a joint and open access salinity monitoring and early warning system aimed at all user levels of the Delta. It will be installed in two provinces: Ben Tre and Tra Vinh, with the intention of scaling up to the entire mouth of the Mekong in the future.

The system will make near-real-time information available through a web platform, as well as through a text messaging service (SMS) for farmers. It will use manual data from individual farmers at field-level and automated data from monitoring stations to produce the most accurate results. This system will be fully open access, meaning that everyone can can access the data at no charge. Though the main focus is on salinity information, selected automated stations will also monitor water quality variables to enable improved environmental management.

Achieving consistent, reliable and timely information to relevant stakeholders is the primary objective of the system. The secondary objective is the building up of historical data which can allow researchers to detect trends and make long-term forecasts, which will subsequently feed into the planning process. This data when linked with an upstream river information system can in the future enable real-time short-term (hours to a few days) forecasting.

The key to this operation working successfully is co-operation and communication between the different stakeholders. Therefore they will all be closely involved with the development of the system and their comments and input will be included within the programme design.

Read more about IFAD's Adaptation for Smallholder Agriculture Programme.