A CATASTROPHE IN THE MAKING

Southeast Asia focus

Sand mining is big business in Vietnam and Cambodia. But its destructive impact – combined with growing flood risks due to climate change – is putting communities and livelihoods in increasing danger.

Billions of tonnes of sand are extracted from the Mekong River every year. It is essential for the construction industry and – due to demand and the acceptance that it has environmental impacts – extraction is now strictly licensed.

Years of research by academics at Southampton have led to a better understanding of the magnitude and often devastating impact of sand mining, as well as the ability to make recommendations to mitigate some of that impact.

Julian Leyland, Associate Professor of Physical Geography, began investigating the situation back in 2012, alongside Steve Darby, Professor of Physical Geography, Dan Parsons, Professor of Sedimentology at the University of Hull, and Dr Chris Hackney, now an Academic Fellow at Newcastle University.

In the course of a project looking at sediment transfer on the Mekong, led by Steve, they witnessed lots of large sand barges and vast amounts of sand being extracted. “Since then, the issue of sand mining has come to the fore,” said Julian. “It’s a catastrophe in the making, as when you take the sediment out from the bed, it can induce bank erosion. People don’t see the big holes from sand extraction because it’s on the river bed, below sediment-laden water, but it ultimately leads to people losing their homes, and to roads and infrastructure being damaged.

“Sand mining is licensed in Cambodia and Vietnam, because the sand is an important resource for building and as such is a precious commodity. It’s well recognised that there is an environmental impact, but there is still lots of illegal activity as it’s big business and big money.”

The arrival of COVID-19 and strict lockdowns in Vietnam in early 2020 led to local reports of a sudden upsurge in illegal sand mining as opportunists struck.

“There was vastly reduced local monitoring of the mining due to people having to stay at home,” explained Julian.

He led a 12-month project alongside Steve, Dan, Chris and Craig Hutton, Professor of Sustainability Science, funded by the Global Challenges Research Fund. They worked with colleagues in Vietnam at Can Tho University and the Southern Institute of Water Resources Research (SIWRR) to undertake remote sensing assessments of whether there had in fact been an increase in mining, and to understand what the physical and socioeconomic impacts of that might be.

They used satellite imagery to monitor how many vessels were on the water – and found that activity had almost doubled.

“We were able to estimate that activity in April 2020 was almost double that of April 2019, with a similar increase of around 75 per cent in May 2020 from May 2019, before dropping back to around the same amount in the following months of 2020,” said Julian.

Through their expertise, the team is able to model different extraction scenarios to illustrate what they would mean for riverbank erosion.

“We’re building maps to show where vessels are, and where the vulnerable areas are, and colleagues in Vietnam are mapping the infrastructure too,” said Julian. “There are places that are more and less vulnerable. Regardless of any recent spikes in activity during lockdowns, it might be really useful in the future if we can point to areas and we can say ‘if you focus mining activity here, it will cause fewer environmental impacts than if you mine downstream here’.”

The team, including SIWRR and Can Tho University, is now involved in a new project funded by the World Wide Fund for Nature (WWF), which will seek to establish a sediment budget for the Mekong Delta and establish plans for future changes and management, including the impacts of sand mining.

Find out more Julian and the team helped to develop, and contributed to, a documentary on illegal sand mining produced by Vice News. The documentary has attracted more than two millions views and can be seen here: https://youtu.be/H4d6LT87pMo