См. также: Грозящая миру песчаная катастрофа (подборка материалов на русском языке)
The mining of sand, a non-renewable resource
Extracts; source; source
Sand and gravel (“aggregates”) are used extensively in construction for the preparation of concrete for buildings and roads, as well as for other applications such as glass, electronics or aeronautics. Added to this are all the aggregates used in land reclamation, shoreline developments and road embankments, plus sand used in industry.
The world’s use of aggregates for concrete can be estimated at 25.9 billion to 29.6 billion tonnes a year for 2012 alone. This production represents enough concrete to build a wall 27 metres high by 27 metres wide around the equator.
This sand and gravel are mined world-wide and account for the largest volume of solid material extracted globally and the highest volume of raw material used on earth after water (about 70-80% of the 50 billion tons material mined/year). Formed by erosive processes over thousands of years, they are now being extracted at a rate far greater than their renewal.
Despite our increasing dependence on the colossal quantities of sand and gravel being used and the significant impact that their extraction has on the environment, the absence of global data on aggregates mining makes environmental assessment very difficult and this issue has been mostly ignored by policy makers and remains largely unknown by the general public.
Cement demand by China has increased exponentially by 430% in 20 years, while use in the rest of the world increased by 60%.
The inland resources of sand from rivers and lakes are not sufficient to meet the ever increasing demand.
River and marine aggregates are now the main sources for building and land reclamation.
The sand that is found in most deserts is paradoxically unsuitable for concrete and land reclaiming, as the wind erosion process forms round grains that do not bind well.
On the other hand, marine aggregate needs to be thoroughly washed to remove salt. If the sodium is not removed from marine aggregate, a structure built with it might collapse after few decades due to corrosion of its metal structures.
Negative effects on the environment are unequivocal and are occurring around the world.
The volume being extracted is having a major impact on rivers, deltas and coastal and marine ecosystems results in loss of land through river or coastal erosion, lowering of the water table and decreases in the amount of sediment supply.
Extraction has an impact on biodiversity, water turbidity, water table levels and landscape and on climate through carbon dioxide emissions from transportation.
There are also socio-economic, cultural and even political consequences.
Mining of aggregates in rivers can change the riverbed, increase flood frequency and intensity. The problem is now so serious that the existence of river ecosystems is threatened in a number of locations and damage is more severe in small river catchments. The same applies to threats to benthic [Bottom dwelling; living on or under the sediments or other substrate/ in an aquatic system] ecosystems from marine extraction.
In some extreme cases, the mining of marine aggregates has changed international boundaries, such as through the disappearance of sand islands in Indonesia.
The Palm Jumeirah, an artificial set of sand islands required 385 million tonnes of sand and 10 million cubic metres of rock. As its own marine sand resources were exhausted, Dubai imported sand from Australia.
upd 2016: new projects
Export of sand to Singapore was reported to be responsible for the disappearance of some 24 Indonesian sand islands. Statistics do not include illegal imports and highlight the need for better monitoring. There is also an alleged illegal sand trade. As the price of sand increases, so does the traffic of sand.
Several options are possible, in combination:
• Reducing the consumption of sand: this can be done for instance by optimizing existing infrastructure, by recycling concrete rubble, or the use of alternative construction materials like wood.
• Setting taxes on sand and gravel extraction to create incentive for economically viable alternatives.
• Reducing the negative impact of extraction: this can be done by modulating the rate of extraction to the rate of renewal of the resource, and by determining the acceptable limit of extraction.
Absence of global data on aggregates mining makes environmental assessment very difficult and has contributed to the lack of awareness about this issue. As a consequence, a large discrepancy exists between the magnitude of the problem and public awareness of it.
Sand trading is a lucrative business, and there is evidence of illegal trading such as the case of the influential mafias in India, and in Morocco, half of the sand – 10 million cubic metres a year – comes from illegal coastal sand mining.
The lack of proper scientific methodology for river sand mining has led to indiscriminate sand mining while weak governance and corruption have led to widespread illegal mining. The lack of adequate information is limiting regulation of extraction in many developing countries. Access to data is difficult, and data are not standardised.
Extracts; source; source
[In India] These sand mafias control large parts of the building industry through bribery and also does not hesitate to apply more brutal methods such as murdering activists; illegal business ties extend to the highest levels of police and government. Illegal sand mining activities are particularly threatening water supply of local communities since river sand is a natural aquifer and its depletion also affects recharging of groundwater.
The depletion of sand sources also leads to bizarre scenes in other parts of the world: in Morocco groups, which are called “sand mafia” there as well, turn up at beaches with hundreds of people and take away entire beaches – the sand is then used to build huge hotel complexes for tourists, which actually come to Morocco to visit these very same beaches.
[…] Dubai used up all its suitable marine sand supplies for an artificial set of sand islands and, after these were exhausted, now has to import sand from Australia for continuing its building madness.
In some extreme cases, the mining of marine aggregates has even changed international boundaries, such as through the disappearance of entire islands in Indonesia – since 2005 at least 24 small islands have disappeared as a result of erosion caused by illegal sand mining. Most of this sand is going to Singapore, which has expanded its surface area by 22% since the 1960s.
In response to this potentially heavy environmental toll many neighboring countries (Indonesia, Malaysia and Vietnam) have now banned exports of sand to Singapore, but this has only shifted the problem to countries such as Cambodia.
“Formed by erosive processes over thousands of years, they [sand and gravel] are now being extracted at a rate far greater than their renewal”.
OUR CIVILIZATION IS literally built on sand. People have used it for construction since at least the time of the ancient Egyptians. Sand of various kinds is an essential ingredient in detergents, cosmetics, toothpaste, solar panels, silicon chips, and especially buildings; every concrete structure is basically tons of sand and gravel glued together with cement.
Apart from water and air, humble sand is the natural resource most consumed by human beings. People use more than 40 billion tons of sand and gravel every year. There’s so much demand that riverbeds and beaches around the world are being stripped bare. (Desert sand generally doesn’t work for construction; shaped by wind rather than water, desert grains are too round to bind together well.) And the amount of sand being mined is increasing exponentially.
Though the supply might seem endless, sand is a finite resource like any other. The worldwide construction boom of recent years—all those mushrooming megacities, from Lagos to Beijing—is devouring unprecedented quantities; extracting it is a $70 billion industry. In Dubai enormous land-reclamation projects and breakneck skyscraper-building have exhausted all the nearby sources. Exporters in Australia are literally selling sand to Arabs.
As land quarries and riverbeds become tapped out, sand miners are turning to the seas, where thousands of ships now vacuum up huge amounts of the stuff from the ocean floor. As you might expect, all this often wreaks havoc on rivers, deltas, and marine ecosystems. Sand mines in the US are blamed for beach erosion, water and air pollution, and other ills, from the California coast to Wisconsin’s lakes. India’s Supreme Court recently warned that riparian sand mining is undermining bridges and disrupting ecosystems all over the country, slaughtering fish and birds. But regulations are scant and the will to enforce them even more so, especially in the developing world.
Sand mining has erased at least two dozen Indonesian islands since 2005. The stuff of those islands mostly ended up in Singapore, which needs titanic amounts to continue its program of artificially adding territory by reclaiming land from the sea. The city-state has created an extra 130 square kilometers in the past 40 years and is still adding more, making it by far the world’s largest sand importer. The collateral environmental damage has been so extreme that Indonesia, Malaysia, and Vietnam have all restricted or banned exports of sand to Singapore.
All of that has spawned a worldwide boom in illegal sand mining.
Today criminal gangs in at least a dozen countries, from Jamaica to Nigeria, dredge up tons of the stuff every year to sell on the black market. Half the sand used for construction in Morocco is estimated to be mined illegally; whole stretches of beach there are disappearing. One of Israel’s most notorious gangsters, a man allegedly involved in a spate of recent car bombings, got his start stealing sand from public beaches. Dozens of Malaysian officials were charged in 2010 with accepting bribes and sexual favors in exchange for allowing illegally mined sand to be smuggled into Singapore.
But nowhere is the struggle for sand more ferocious than in India. Battles among and against “sand mafias” there have reportedly killed hundreds of people in recent years—including police officers, government officials, and ordinary people.
THE BROAD, MURKY Thane Creek, just outside Mumbai, is swarmed with small wooden boats on a recent February morning. Hundreds of them are anchored together, hull to hull, in a ragged line stretching at least half a mile.
Each boat carries a crew of six to 10 men. One or two of them dive down to the river bottom, fill a metal bucket with sand, and return to the surface, water streaming from their black hair and mustaches. Then two others, standing barefoot on planks jutting from the boat, haul up the bucket with ropes. Their lean, muscular physiques would be the envy of any hipster gym rat if they weren’t so hard-earned.
Pralhad Mhatre, 41, does about 200 dives a day, he says. He’s worked the job for 16 years. It pays nearly twice what the pullers get, but it’s still not much—about $16 a day. He wants his son and three daughters to go into some other profession, not least because he thinks the river’s sand will soon be mined out. “When I started, we only had to go down 20 feet,” he says. “Now it’s 40. We can only dive 50 feet. If it gets much lower, we’ll be out of a job.”
Meanwhile, India is fitfully taking steps to get sand mining under control. The National Green Tribunal, a sort of federal court for environmental matters, has opened its doors to any citizen to file a complaint about illegal sand mining. In some places villagers have blocked roads to stop sand trucks, and pretty much every day some local or state official declares their determination to combat sand mining. Sometimes they even impound trucks, levy fines, or make arrests.
But India is a vast country of more than 1 billion people. It hides hundreds, most likely thousands, of illegal sand mining operations. Corruption and violence will stymie many of even the best-intentioned attempts to crack down. At root, it’s an issue of supply and demand. The supply of sand that can be mined sustainably is finite. But the demand for it is not.
Every day the world’s population is growing. More and more people in India—and everywhere else—want decent housing to live in, offices and factories to work in, malls to shop in, and roads to connect it all. Economic development as it has historically been understood requires concrete and glass. It requires sand.
“The fundamental problem is the massive use of cement-based construction,” says Ritwick Dutta, a leading Indian environmental lawyer. “That’s why the sand mafia has become so huge. Sand is everywhere.”