Mekong River
Mekong River
(Photo : Pixabay)

New research undertaken as part of a project led by the University of Southampton has shown sand mining causes river beds to lower down - leading to instability of riverbank and placing lives at hazard.

Researchers, whose study was published in Nature Sustainability, focused on the Mekong River - the "lifeblood" of Southeast Asia.

Chris Hackney, a post-doctoral research associate at the University of Hull who led the study, said concrete construction had grown massively with the world presently undergoing speedy population boom and urbanization. The progress, according to Hackney, fuels unprecedented sand demand so much so that it is now the 'most consumed resource' on the planet next to water.

The studies became undertaken as a part of a NERC funded challenge led by using Professor Stephen Darby at the University of Southampton, which is studying the impact of climate change on the fluctuation of sediment in the Mekong.

Stephen Darby, a study co-author who serves as a professor of Physical Geography in Geography and Environmental Science at the University of Southampton, explained that much of the sand used in producing concrete comes from the world's big sand-bedded rivers, just like the Mekong.

Darby added there has long been a problem that sand mining from the Mekong is causing severe problems, including the adverse effects unsustainable sand mining has on riverbank erosion."

The research team used sonar surveys to understand how much sand is transported via the Mekong, either in the water column or on the river bed. The sonar surveys also found out how much sediments are being taken with the aid of sand miners.

The sonar pics show giant holes 42 meters in length and eight meters deep on the river bed due to sand elimination from the Mekong. By comparing the natural sand shipping costs with the estimates of sand extraction, the team estimated that sand is being removed from the Mekong five to nine times more than the price at which sand is replenished with the aid of the river's natural sand transport processes.

The crew had been then able to examine how the decreasing of the river bed increases the threat of dangerous riverbank collapses using measurements of the form of the river banks made via Terrestrial Laser Scanner. 

Dr. Julian Leyland of the University of Southampton, who done the TLS surveys, said that lowering the river bed by two meters would cause most of the river banks along the Mekong to collapse. Dredging pits, according to Leyland, usually exceeds eight meters in depth. 

"It's clear that extreme sand mining is answerable for increased rates of riverbank erosion that the locals were saying in recent years," Leyland said.

Excessive sand mining at the Mekong and other predominant rivers worldwide increases environmental and social consequences without the proper regulation, Dr. Hackney warned.

While sand is a resource used in global construction and mined from rivers and coasts across the world, the researchers suggest that stronger regulation of unfettered quarrying is needed to keep away from the dangers that riverside communities are facing due to the profound effects that excessive sand mining is having on rivers.