The story so far: A much-needed ban on river sand mining in Kerala has instead spurred more stone quarrying, and many of these quarries are located near protected areas, according to a new report from scientists in the State.
Why did Kerala ban river sand mining?
Kerala banned river sand mining in January 2016 to protect its rivers and their ecosystems from the degradation caused by excessive extraction. After the ban, M-sand, an artificial alternative produced by crushing hard rock such as granite into fine particles, quickly became a popular alternative, leading to the rise in stone quarrying.
To assess the impact of the mining ban, scientists from the National Institute of Technology (NIT) Calicut analysed the expansion of 72 quarries they'd identified within 10 km of protected areas. Using GIS and Google Earth Pro, they compared the quarries' average annual expansion three years before the ban to their expansion in 2016, immediately after the ban kicked in. They also analysed expansion in the three following years.
In a paper in The Extractive Industries and Society, the team reported that in 2016 alone, the quarries expanded by 174% in area, with some more than doubling in size. After comparing their data with that from other parts of the world, the researchers concluded that more quarrying may spell trouble for the region's biodiversity.
Where are the quarries located?
"Unfortunately, a good number of these quarries are near protected areas," George Varghese of NIT Calicut and one of the study's authors, said. "Thus, although done with good intentions, the river sand-mining ban resulted in an unanticipated impact on biodiversity."
The team also identified three quarries of particular concern, all within 10 km of the Malabar Wildlife Sanctuary in Kozhikode and Wayanad districts. These quarries grew 232% in size in 2016 alone. Three more quarries, within the buffer zone of the Silent Valley National Park across the Palakkad, Malappuram, and Nigliris districts, doubled in size as well.
Why is sand-mining a problem?
The team's paper sheds light on the complexity of micro-level sand mining and extractive activities on natural resource trade flows, livelihood welfare conundrums, and socioecological systems, Matovu Baker, a research associate at the National Taiwan Ocean University in Keelung said.
Dr. Baker, who studied the effects of river sand mining at Amrita Vishwa Vidyapeetham, said the paper demonstrates "emerging socioecological system trade-offs that are less documented and could lead to blue injustices," a counter-movement focusing on injustices to "small-scale fishing communities in coastal areas".
"The huge demand for the M-sand has drastically increased the quarrying area within a very short period," Aznarul Islam, associate professor at Aliah University in Kolkata, said.
Dr. Islam and his colleagues have studied the consequences of riverbed sand mining on the Mayurakshi river in the 50 years spanning 1970 to 2020, using topographical maps, satellite images, and field-based measurements.
While sand mining had a "mild impact" on the shape of the river channel between 1970 and 2010, a phase of accelerated mining phase 2010-2020 "vehemently altered the channel morphology," he said.
"The problem of river sand mining was a worrying factor for the river and its ecology," Dr. Islam said. "The strict ban on river sand mining [in Kerala] increased the manufactured sand mining at a rapid pace, which actually reduced the quality of the ecosystem and biota.
How is demand for sand changing?
India has been recording an ever-increasing demand for river and marine sand, especially at its major urban centres, according to the India Rivers Forum. The States whose rivers have been suffering the most as a result include Jharkhand, West Bengal, Tamil Nadu, and Karnataka; Odisha, Tamil Nadu, and Kerala have also been reporting considerable marine damage.
The scope and severity of consequences vary depending on several on- and off-site mining activities and interactions between demand and supply, Dr. Baker said. He highlighted the example of Chavara village in Kerala's Kollam district, where the removal of sediments had affected the migratory routes of fish.
"The worst-case externalities exist in less-protected or remote zones, for example in Tamil Nadu," he added.
Several legal, policy, or research strategies could offer solutions, but they have to be coherent and sustainable, per Dr. Baker.
T.V. Padma is a science journalist in New Delhi.