Recently, a 21-member research team led by Matt Kondolf, Professor of Landscape Architecture and Environmental Planning at University of California, Berkley has recently published a scientific article titled ”Save the Mekong Delta from drowning” on Science. In this article, the authors warn that sea level rise may drown Mekong Delta by 2100 if no urgent actions are taken. They also point out that further risk factors include over-pumping of groundwater and unsustainable sand mining for construction, as well as rapid hydropower development upstream. The research team calls for rapid and urgent action from all six Mekong countries, and better management of water and sediments within the delta could mitigate the risk.
Susanne Schmeier, an associate professor at IHE Delft Institute for Water Education and a member of the research team, also published a news article introducing the research paper.
“It’s hard to fathom that a landform the size of the Netherlands and with a comparable population might disappear by the end of the century,” said lead author Matt Kondolf, Professor of Landscape Architecture and Environmental Planning at University of California, Berkley. “Yet, like any river delta, the Mekong Delta can only exist if it receives a constant sediment supply from its upstream basin and water flows to spread that sediment across the delta surface build land at a rate that is equal or greater than global sea level rise.”
Rapid and urgent action is needed, Schmeier added.
“Efforts by national governments, regional organizations and international actors, such as development agencies and banks, as well as the private sector and civil society, are all needed if the Mekong delta is to have a chance,” she added. “We need basin-wide transboundary, fast and concerted cooperation among all partners.”
In the Mekong, water and sediment flows are increasingly endangered. Countries in the basin develop renewable hydropower, which has system-scale impacts as dams trap sediment and reduce downstream sediment flows. Sand minding that feeds a burgeoning real estate sector and land reclamation compounds the problem.
In the delta itself, high dikes built to control floods and enable high-intensity agriculture prevents flood waters from overflowing onto the delta surface and deposit fertile sediment. In addition, unsustainable groundwater use makes the delta surface sink several centimetres a year.
The authors identify measures that would significantly increase the lifetime of the delta. Dams could be designed to enable better sediment passage, placed in a strategic way that reduces their downstream impacts, or replaced by wind and solar farms where possible. Sediment mining should be strictly regulated, and use of Mekong sand could be reduced through sustainable building materials and recycling.
Intensive agriculture in the Mekong Delta should be reevaluated for its sustainability, and natural solutions for coastal protections should be implemented on a large scale along the delta’s coasts. All these measures are feasible and have global precedents.
However, they face opposition by stakeholders such as the sand mining industry, and they require cross-country coordination that can be difficult to achieve.
Countries would also need to agree that the sustenance of the Mekong delta is an important regional policy objective. In Vietnam, where most of the delta is located, some recent policies try to counter some symptoms of a sinking delta, but there is little acknowledgement of the existential risk to the delta, nor ambition to work on truly systemic solutions.
Story by Susanne Schmeier
