BAGUIO CITY – US experts predicts ground subsidence in magnetite mining areas in North Luzon using high-tech “remote sensing” in a published article on January 28, 2016.
In their article titled Characterization of Black Sand Mining Activities and their Environmental Impacts in the Philippines Using Remote Sensing, geologist Estelle Chaussard of the State University of New York and political scientist Sarah Kerosky of the University of California, have proven that through Remote Sensing, data can be gathered “to monitor, control and respond to black sand mining activities and their environmental and societal impacts.”
Remote Sensing is a method analyzing data from remote satellite images to “sense” a change in the geophysical maps of target areas. The study uses the Interferometric Synthetic Aperture Radar (InSAR) to assess which communities with black sand mining activities are most vulnerable to sea level rise and impacts of climate change. For years, InSAR has successfully detected ground deformations linked with many geohazards such as earthquakes, volcanic eruptions and land subsidence due to groundwater extraction.
The study targeted existing 20 black sand mining sites that need focus from the data verified from MGB data, news, and reports of peoples’ organizations. They also enlisted the help of local environment organizations, Amianan Salakniban conveners – Defend Ilocos and Federation of Environmental Advocates in Cagayan (FEAC) to confirm the existence of black sand mining activities in target areas.
According to their data from 2010 up to 2013, there have been 28 black sand mining operations in Cagayan and 18 in Ilocos Sur. Most of which are illegal.
In the results of their study, “sites with subsidence rates of 1.8 and 3 cm/ a year are projected to be underwater in 50-70 years (while those with) subsidence rates of 4.3 and 4.6 cm/ year are projected to be underwater in 30- 40 years.”
Critical areas they have detected to have been experiencing land subsidence from 2007 to 2013 are Lingayen (4.8 cm/yr), San Marcelino (1.3 cm/yr), Candon City (3.0 cm/yr), Santa Lucia (4.3 cm/yr), Dagupan (4.3 cm/yr), Santa Maria (2.5 cm/yr), Masinloc (1.8 cm/yr), and Balanga (2.6 cm/yr).
In their conclusion, they highlighted the threat posed to coastal towns nearby black sand mining sites. “Rapid subsidence results in high exposure to flooding and seasonal typhoons, and amplifies the effect of climate change–driven sea level rise. We show that several coastal areas will be at sea level elevation in a few decades due to the rapid subsidence. Since subsidence likely continues to affect the areas even decades after the cessation of mining activities due to the disruption of the sediment budget, characterization of the temporal evolution of land subsidence with longer SAR temporal coverage will be critical to mitigate environmental and societal effects of black sand mining activities.”
Amianan Salakniban, the widest network of environment and human rights groups in Northern Luzon calls for the halt of magnetite mining operations in Cagayan and Ilocos to solve this problem.
“The outcome of their study is very disturbing (nakakatakot). We know the negative effects of black sand mining as experienced by the communities based only on observation, but seeing proof based on a high tech scientific study with our own eyes should really bother us even more and challenges us to act to change this alarming future,” said Fernando Mangili, Amianan Salakniban Spokesperson.
According to Mangili, most black sand mining operations in NL coastlines are illegal, foreign and backed by political dynasties in provinces.
“If our government especially the LGU of areas mentioned in the study will not address this problem, a great catastrophe is very likely to happen,” Mangili added. “We should act now before we have another Yolanda in Northern Luzons’ coasts. Let us protect the future of our people in the coastal areas by stopping large-scale magnetite mining in the Philippines.”
They also called for government agencies such as MGB to use this technology to find illegal mining activities in North Luzon and apprehend them immediately.
“A lot of times, illegal mining activities continue even though the communities report it to authorities. This is true in the case of illegal Chinese mining in Cordon Isabela that up until now, the MGB hasn’t stopped it despite the community’s protests. People in Cordon still report that illegal mining is very much alive in the area.”