Julian Leyland, University of Southampton
Sand underpins everything from skyscrapers to smartphones. Sharp sand (as opposed to rounded desert sand) is the key ingredient in concrete, while high-purity silica sand is essential for making the silicon chips that power our digital devices.
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Yet the relentless extraction of this seemingly abundant resource is pushing river systems to the brink of collapse, displacing communities and fuelling a billion-dollar black market.
Despite its critical role in modern society and urban development, the environmental and social effects of sand mining remain largely hidden from public scrutiny. The UN’s environment programme (Unep) warns that global sand consumption now exceeds 50 billion tonnes annually.
That’s way beyond estimated natural replenishment rates of 15 billion to 20 billion tonnes annually. Despite this, sand mining remains largely unregulated, with devastating ecological and social consequences.
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Rivers are the lifeblood of ecosystems and communities. They transport sediment, shape landscapes and sustain wildlife.
But our team’s research on the Lower Mekong river reveals that sand mining is depleting sediment stocks at an alarming pace, causing riverbeds to lower and banks to erode. However, new hi-tech surveillance could improve the enforcement of sand mining regulations and improve resilience for these riverbed communities.
As sea levels rise and riverbeds are lowered due to sand mining in the Mekong delta, saltwater spreads further upstream into freshwater areas. This threatens agricultural productivity in the “rice bowl” of south-east Asia. Sand mining also undermines the delicate balance of ecosystems like the Tonle Sap lake – a critical fish nursery and food source for millions.
The Mekong river in Asia flows through six countries, supporting more than 60 million people. In Cambodia, sand mining has become a multi-million-dollar industry, driven by a construction boom fuelled by Chinese investment.
Along the Mekong river, my team has documented sites of severe bank erosion using hi-tech equipment. Voi Thy, a 43-year-old resident of Roka Koang commune, has had to move her house multiple times since 2016 due to collapsing riverbanks – a direct consequence of sand mining.
Although existing research focuses exclusively on the physical damage, sand mining also erodes cultural and communal ties. Rivers are not just sources of water and food. They can be spiritual and cultural anchors. https://www.youtube.com/embed/kyOYs-g6FfI?wmode=transparent&start=0 Julian Leyland explains how sand mining threatens river ecosystems.
In Cambodia, traditional fishing practices and sacred sites are disappearing as rivers are stripped of their sediment. For communities that have lived alongside these waterways for generations, the loss is profound, severing connections to their heritage and identity.
The loss of livelihoods is equally devastating. Fishers and farmers, once reliant on the river’s bounty, are seeing their incomes vanish.
Many, like Vanna, a local fisherman who features in our Lost Lands documentary, are forced to leave their rural homes for cities, where they often find precarious work in poorly regulated industries. This migration fractures communities and places additional strain on urban infrastructure, creating a ripple effect of social and economic challenges.
The Cambodian government denies that dredging is responsible for the erosion, claiming it stabilises riverbanks – a claim disputed by our team. Strengthening cross-border governance and enforcing extraction limits are critical to addressing this crisis. But time is running out.
The global sand trade is valued at over US$2.3 billion (£1.8 billion) annually, with demand predicted to double by 2060. Much of this economic gain is concentrated in wealthy cities, while the costs are disproportionately borne by local communities in extraction regions. In many sand-rich areas, people face displacement as their riverbanks erode and homes collapse into the water.
The high value and ease of sand extraction have led to the rise of illicit mining networks. In some areas, so-called “sand mafias” control extraction sites, using intimidation and violence to secure their dominance. The lack of legal oversight fosters corruption, with mining permits often being issued through opaque processes. That can further marginalise local communities.
Given the clandestine nature of illegal sand mining, monitoring extraction rates has historically been difficult. However, recent advances in remote sensing and deep learning technology offer new opportunities for surveillance.
As part of our new Hidden Sands project, we are using high-resolution satellite imagery and ground-based cameras to map riverbed sand mining across the Mekong delta. With more accurate real-time insights into the volumes of sand being extracted, policies can be more effectively enforced.
Sustainable sand use
A growing body of organisations, such as the conservation charity World Wide Fund for Nature and Unep, are calling for urgent regulatory intervention and alternative sourcing strategies. Building on the conclusions of previous work, sustainable sand management in the Mekong needs to drastically change.
Stricter regulations, and enforcement of those laws, would ensure more sustainable sourcing of sand and help curb illegal mining activities. The development of alternative recycled construction materials, such as manufactured sand from industrial byproducts, could reduce the pressure on river sources of sand.
Once extracted or manufactured, fairer distribution of those resources can be better achieved through community-led conservation and employment initiatives, for example, that can build resilience and protect cultural heritage of traditional practices.
Without intervention, the unchecked exploitation of river sand will continue to degrade ecosystems, threaten wildlife and exacerbate social and economic inequalities. Governments, industry leaders and researchers must collaborate to ensure sand extraction is sustainable and equitably managed. Until then, global demand for sand shows no signs of abating.
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Julian Leyland, Professor of Physical Geography, University of Southampton
This article is republished from The Conversation under a Creative Commons license. Read the original article.