A 21st century construction boom is driving unregulated sand mining around the world - eroding rivers and coastlines, disrupting ecosystems and hurting livelihoods.
From Shanghai to Seattle, the world’s cities are built on sand - massive amounts of sand. It’s in the cement and concrete that make the bulk of most buildings. The glass in those buildings’ windows is made with sand, too. So is the tarmac laid onto the roads around them.
Sand is the planet’s most mined material, with some 50 billion tons extracted from lakes, riverbeds, coastlines and deltas each year, according to the United Nations Environment Programme. Per person, that’s about 6,570 kilogrammes (14,500 pounds) per year - more than an elephant’s weight in sand.
Demand for sand is only expected to grow, as the global population continues to climb, cities expand and countries further develop. But in much of the world, sand mining faces little to no government scrutiny. There are scant regulations for protecting the environment, or workers’ safety. And few entities monitor or document the trade for its impact.
The result is that sand is being extracted far more quickly than it can naturally be replaced. That’s causing environmental damage and, in some cases, jeopardising livelihoods.
“This isn’t an issue that’s relevant for only some places. Sand is a critical material for every country,” said ecologist Aurora Torres at the Universite Catholique de Louvain in Belgium. She researches how sand mining can affect both the natural world and people’s well-being.
But many people still “don’t know about these problems,” Torres said. “The number of extraction sites is just huge, which makes it hard to monitor. And we researchers still don’t know many things about the magnitude of the impacts.”
Demand for sand has surged in the last two decades, thanks to urbanisation and construction in China, India and other fast-developing countries.
In just the last 10 years, China’s cities went from housing 51% of the national population to about 60%, according to the National Bureau of Statistics of China. To handle the housing pressure, cities have expanded, adding new structures and building out roads.
China already has used more cement since 2006 than was used in the United States during the entire 20th century.
China is not alone in its drive to build infrastructure and housing. In fact, sand is in such demand that cargoes are regularly shipped around the world. In 2018, those trades were worth some $1.9 billion, according to Harvard’s Atlas of Economic Complexity.
The vast majority of mined sand, however, gets used in the country where it was extracted. In parts of Africa, sand mining has helped people build sturdier homes. But in some cases it has also left the ground pocked with open pits, which can fill up in rainy seasons, providing breeding ponds for disease-carrying mosquitoes.
People have suffered directly from illegal activity as well. In India, 193 people died in accidents related to sand mining operations or sites in 2019-2020, according to a January report by the rights group South Asia Network on Dams, Rivers and People. About half of those deaths occurred from drowning in mining pits, including 76 “minor kids or young children or teenagers who entered the river to have a bath, unaware of deep pits in the riverbed".
The right kind of sand
It’s hard to imagine a shortage of sand. It covers millions of square kilometers across the world’s many deserts, piled in some places into towering dunes.
But desert sand is useless for construction. The wind-weathered grains are too small and smooth for binding in concrete. Sea sand has similar properties from being tossed by ocean currents. But it can be used in land reclamation projects, such as in China, Singapore and Hong Kong.
The sand that’s ideally sized, shaped and cut out for construction comes from shorelines and the beds of rivers and lakes. This is also where to find silica sand, which is melted down to make glass for everything from windshields to smartphone screens.
Some countries, including China and the United States, have begun producing “crushed rock” as an alternative, blasting into rock beds and then grinding the rubble down to cement-suitable aggregates. But that requires investment in both equipment and power to run the machinery, which many small, informal mining operations don’t have.
Scientists have called for a global programme to monitor and manage the industry as a first step to controlling the plunder. Standardising the industry would also mean miners don’t have to become criminals to operate.
Experts also note a need for more materials recycling. Already, the mass of all human-made materials is greater than that of all living things on Earth, according to research published in December in the journal Nature.
“Some people talk about a global sand scarcity, which doesn’t make sense since we don’t have any data that could prove that,” said researcher Torres. What’s needed is more research to map out where sand exists and determine mining volumes “to ensure supply on an increasingly crowded planet without compromising biodiversity”.
Mining hot spots
Sand mining took off only decades ago. The method of extraction depends on where the sand is located. On land or along rivers, it is often dug up with backhoes, shovels or bare hands. Along coastlines, miners use dredging boats or suction pumps.
The damage from sand extraction can be seen clearly in satellite images, with coastlines eroded, ecosystems destroyed, and even entire small islands in Southeast Asia wiped off the map. Rivers can see major environmental disruption, including the erosion of river banks to the point where they collapse, and the destruction of breeding habitats for riverine animals including birds and crocodiles.
Small-scale mining operations along Vietnam’s Mekong River and its tributaries have robbed the region of sand, while upstream dams prevent it from being replenished. As a result, the delta is sinking about 2 centimetres (0.75 inches) each year, according to local officials and Duong Van Ni, an expert on the Mekong River at the College of Natural Resources Management of Can Tho University, the largest city in the Mekong delta region.
Rapid erosion, meanwhile, is destroying homes and threatening livelihoods across the Southeast Asian country’s largest rice-growing region.
The impact of sand mining is clear in this stretch of the Da Dang River, in the Vietnamese province of Lam Dong. River banks have badly degraded over a five-year period, illustrated in these satellite images released by Digital Globe and Airbus and analysed by Earthrise Media.
Da Dang River - Vietnam
Many places around the world bear the scars of rampant sand extraction. In southern India, for example, extensive sand mining along the Palar River fed a construction boom in the city of Chennai. In the images below, the dry, sandy river bed appears to have been scraped and excavated over the years, leaving a large depression now filled with water.
A state court intervened in 2013 to ban mining in the Palar. But that ban expired in 2018.
Palar River - India
When rivers are dredged, the evidence can be hidden beneath the water until disaster occurs.
Local politicians near India’s Phalguni River blame the extraction of sand for undermining the foundations of the Mullarapatna Bridge, causing it to collapse just 30 years after it was built. The bridge was located near Mangaluru in the southern state of Karnataka, one of India’s top spots for rampant sand mining, according to the Indian Bureau of Mines.
Mangaluru - India
In the rivers of Azad Kashmir in northern Pakistan, at least seven different sand mining operations can be seen in this satellite snapshot from May last year.
Azad Kashmir - Pakistan
Near the southwest Indian town of Alappad, beaches have been eroding gradually for six decades. But sand mining has caused wide stretches to vanish in the last decade alone.
Satellite images from 2003 to 2019 reveal deep cuts into the sand on the beach, as well as watery space where sand, trees and other vegetation were removed entirely.
Alappad - India
Just like rivers, freshwater lakes can hold vast amounts of coarse sand, ideal for construction. One of the most obvious examples of sand extraction is in Poyang Lake, the largest freshwater lake in China, located in Jiangxi Province.
The lake’s inflow and outflow of water have been disrupted in recent years by sand mining, as well as by dams and landscape changes. In 2020 the lake filled to its highest recorded level, prompting authorities to declare a “red alert” as flooding threatened surrounding areas.
This 2017 image of just a portion of the lake shows dozens of ships dredging sand or carrying it away.
Poyang Lake - China
Since June, Chinese dredgers have swarmed around the Taiwan-administered Matsu Islands, dropping anchor and scooping up vast amounts of sand from the ocean bed for land reclamation projects in China.
Aside from Matsu, where 13,300 people live, Taiwan’s coast guard says China also has been dredging in the shallow waters near the median line of the Taiwan Strait, which has long served as an unofficial buffer separating China and Taiwan.
Last year, Taiwan expelled nearly 4,000 Chinese sand-dredgers and sand-transporting vessels from waters under its control, most of them in the area close to the median line, according to the coast guard. That’s a 560% surge from the 600 Chinese vessels repelled in all of 2019.
Chinese sand mining vessels expelled from Taiwanese waters
At one point last year, more than 200 Chinese sand-dredging and transport boats were spotted operating south of Nangan, the main Matsu islet, three Taiwanese officials told Reuters. Lin Chie-ming, the coast guard commander, recalled encountering a similar scene with about 100 Chinese boats on Oct. 25. His team expelled seven Chinese vessels that breached Matsu waters that day.
Matsu Islands - Taiwan
While scientists advocate for more oversight of the sand industry, and more effort by industries to recycle old materials, they are also exploring other solutions.
Two years ago, a group of researchers noted that, as climate change speeds the melting of ice in Greenland, more water is flowing toward the ocean carrying sediments that are deposited at the coastline - sediments that could potentially be used in the island’s construction industry or sold to boost the Greenland economy.
Within days of the study’s publication in the journal Nature, Greenland’s politicians “decided they wanted to investigate this”, said co-author Mette Bendixen, who researches how climate change is impacting the Arctic landscape at the University of Colorado Boulder’s Institute of Arctic and Alpine Research.
It’s still unclear if the sand is even suitable for construction. Bendixen tried once to row out in a dinghy to collect samples, but turned back after getting caught in the currents.
But while mining Arctic sand might help Greenlanders, it’s far from a solution to meet the global sand appetite. “The key is really to find ways to monitor the way we’re using sand right now,” she said.
Marco Hernandez, Simon Scarr and Katy Daigle
Earthrise Media; Maxar Technologies; Airbus; Landsat, NASA. U.S. National Oceanic and Atmospheric Administration (NOAA). United Nations Environment Programme (UNEP). U.S. Geological Survey. National Bureau of Statistics of China. China’s Ministry of Natural Resources.