In 2016, the longest-running conflict in the Western hemisphere drew to a close. Colombian President Juan Manuel Santos signed a peace agreement with the Revolutionary Armed Forces of Colombia, ending 50 years of violence that had seen hundreds of thousands killed and 7 million Colombians driven from their homes—the highest number of internally displaced people the world as of 2016.
However, many Colombians still feared returning to the countryside, thanks to war’s other lasting legacy: landmines. While no one knows how many mines pepper the country, from 2008 to 2014, Colombia suffered the world’s second-highest landmine mortality rate. Only Afghanistan had more deaths. Victims have since dropped from a high of over 1,000 per year to fewer than 100, but the country is still considered to be heavily mined.
The first step to eliminating the mines is finding them. Mine detection technologies have progressed very little since they were first developed in the aftermath of World War II and are still almost primarily based on metal detection. This makes Colombia’s predicament even more costly and time consuming than usual. Unlike the majority of affected nations, Colombia’s landmines are homemade and typically contain very low metal content.
While domestic and international landmine removal groups go about the painstaking task of ridding the country of those stealthy bombs the old-fashioned way—literally digging up suspected mined areas, inch by inch—Colombian researchers have taken it upon themselves to create cutting-edge technological fixes that they soon hope will expedite the process by an order of magnitude.A member of the HALO Trust, a nonprofit that removes war debris, treads carefully during a defining operation in Colombia.
“This is no longer basic research, but application,” says Fernando Cristancho, a nuclear physicist at the National University of Colombia. He and his colleagues have developed a specialized robot that uses neutrons to identify mines buried below the soil, while other colleagues are working on devices that weed out the false positives that frequently bog down landmine hunts. Still others have pursued machines that use electromagnetic waves to remotely detonate and destroy landmines from a distance.
“We’re putting all of our energy, effort, students, and time into trying to advance this,” says Felix Vega, an electrical engineer at the National University of Colombia. “We’re trying to to solve our own problems.”
A Daunting Clean-Up
The conflict in Colombia began on ideological grounds, with disenfranchised rural citizens calling for a transformation to Marxism-Leninism. As the fighting dragged on, however, guerrillas began to lose sight of their political agenda and focus more on profit-driven crime, including cocaine production and illegal gold mining. Landmines began appearing in the early 1990s, largely as a way to protect smuggling routes, jungle camps, and illicit crops. Around 11,500 people in Colombia have been injured or killed by those hidden explosive devices since then—though experts believe many more deaths have gone unreported.
Landmines, in general, come in two forms: ones meant to destroy tanks and other vehicles and ones meant to stop humans. Colombia only has the latter: “It’s really difficult to get a car into the middle of a forest,” says Jairo Alexis Rodriguez, a physicist and director of research at the National University of Colombia.
Even more uniquely, all of the mines left in Colombia today are homemade improvised explosive devices (IEDs) rather than commercially-produced military grade ones. Rebels fashioned them with whatever materials they happened to have on hand, including PVC pipes, plastic bottles, and various chemicals. They purposefully left metal out to prevent the military from identifying them with metal detectors, and the variety of substances they used has also made it more difficult to train sniffer dogs to help with cleanup.Many landmines in Colombia are IEDs rather than commercially made and almost entirely devoid of metal, including this one, made from a plastic bottle and plunger.
That leaves experts with a daunting challenge: how to find mines buried in thick jungles and rugged mountains in a country over twice the size of France with little to no help from traditional demining tools?
Getting a handle on the scope of the problem is a first step, according to Chris Ince, Colombia country program manager at the HALO Trust, a non-profit organization dedicated to cleaning up debris left over from war. “There is an urban myth that the entire country is mined,” he says. “The reality of the situation is that, until a detailed survey is conducted, the true level of contamination remains unknown.”
To do this, Ince and other experts hire community members (and, in some cases, former guerrillas) living near suspected mine fields. With their help, they conduct extensive interviews to determine if landmines are indeed present and, if so, where, exactly, they occur. Because guerrillas wanted local people on their side, they often told rural residents where the mines were so the residents could avoid those areas. After interviewing up to 1,000 people at a given site, Ince and his colleagues use those data to home in on an area of likely contamination.
HALO has cleared more than 500 landmines from over 150 minefields in Colombia. But the task is excruciatingly labor intensive. Some mine fields are a seven-hour walk from the nearest road and require using mule trains to ferry supplies back and forth. Reaching the site is just the beginning. Given that metal detectors have limited use, deminers meticulously dig up the soil of the entire site (sans large shrubs and trees) to a depth of just over a foot. “Up to 70% of our day is spent in vegetation-clearing activities,” Ince says. “You’re literally hand digging the entire area.”A man digs around a landmine in a HALO demining operation in 2015.
Cristancho adds that, though certain vegetation is left in place, these operations cannot help but cause significant environmental damage. “It looks like a war zone,” he says. “If you take away 15 centimeters of soil all over the place, the earth gets dry and then the area gets washed away in the next rain.”
The method also takes forever. Whereas experts working with a metal detector may cover an area of 24 square yards in a day, in Colombia, they typically cover just one to six square yards. “Having all kinds of procedures in place guarantees high standards of safety but makes the process slow and logical,” Ince says. “One of the biggest things we have to do is keep deminers focused, because it’s like finding a needle in a haystack.”
Modernizing Mine Hunting
Yet there could be a better way. As Diego Torres, a physicist at the National University of Colombia, asks, “What if we can develop technologies that immediately identify and destroy mines?”
For years, Torres and others at universities throughout Colombia quietly pursued landmine-related technologies in near secret to avoid politicizing their work and raising security concerns. After peace came, “we discovered that groups located just 100 meters from each other had been working in the shadows on the same things for ten years,” Torres says.
For the past decade, Cristancho and his colleagues, for example, have been perfecting a landmine-detecting robot that they believe would spare deminers from having to dig up entire tracts of land. The Alexbot, as they call it, was inspired by existing oil industry technology to measure soil humidity by using neutrons. As Cristancho says, “We didn’t invent this technology, we just put the general pieces together to make it fit a specific task.”Nuclear physicist Fernando Cristancho demonstrates the features of the Alexbot, a robot that he and his colleagues created to detect landmines using neutrons.
The six-wheeled Alexbot—which bears a slight resemblance to the Mars rover—sweeps a mechanical arm back and forth above the ground as it slowly proceeds forward in an area suspected of having landmines. The arm holds a container with small amounts of californium-252 which emits neutrons used to map things hidden below. The resulting data are based on the rate and speed at which neutrons backscatter when they encounter carbon, hydrogen, nitrogen, and oxygen—all common components of explosives.
In field testsearlier this year, the Alexbot successfully detected a deactivated IED—donated to the lab by the Colombian military—that the researchers had buried in diverse soils and at different depths and humidities. In other trials, the team was able to detect buried IED-like objects containing just 3.5 ounces of chemicals typically used in landmines. Next steps, Cristancho says, they’ll perform many more field trials and use machine learning to better teach Alexbot what to look for.
Cristancho is not the only researcher working on such problems. His university and Los Andes University has produced around half a dozen PhD students whose work specifically focused on demining techniques. Other scientists are pursuing various solutions as well. The key, Torres says, is to design a suite of technologies that not only expedite the process of finding and deactivating landmines but that also add layers of redundancy. “You can always miss something,” he says. “You need to create more techniques if you want to be sure that you have completely eliminated the threat so people can return to their homeland.”
Vega and his students, for example, are creating another type of landmine detection device that uses ground penetrating radar to map objects buried up to eight inches beneath the soil. They hope this will eventually eliminate the time-consuming problem of false positives, which may constitute up to 99 out of 100 detections using conventional methods.
But such projects are in need of greater support. “These devices are used to avoid people dying and suffering, but that doesn’t bring in much money,” Cristancho says.
In one case, Vega and fellow researcher Francisco Roman had created a patented landmine-destroying device that used directed electromagnetic waves to safely activate mines at just over 80 feet away. It was shelved due to lack of funding. “At the end of the day, we developed a concept that worked, but we had to stop at that stage,” Vega says. “Going to the next phase required more money than was available.”Fernando Albarracin-Vargas (left), Sergio Gutierrez, Felix Vega, and Diego Alejandro Torres Galindo at the National University of Colombia's landmine detecting test site. Albarracin-Vargas and Gutierrez are using ground penetrating radar to map objects buried below.
Given such constraints, Ince doubts that the high-tech devices being developed by Colombian scientists will be ready for deployment in the near future. “Probably in the long term some, of the more esoteric technologies being considered will lead to something capable of helping,” he says. “But the chances of taking something from a prototype to a commercially viable and cost-effective technology—one that doesn’t further complicate security requirements within the framework we operate in—is more difficult.”
Cristancho argues that the time scale is not a problem—if only funding were available. With $800,000 and eight months of testing, he believes the Alexbot could be deployable. “We have the right people, and we know what we’re doing,” he says.
Colombia does have an obligation to see that through. The nation is a signatory to Mine Ban Treaty, a United Nations convention that seeks to end the use of antipersonnel landmines worldwide. As part of that treaty, Colombia pledged to become landmine-free by 2021—a goal that HALO and other demining groups are striving to meet. But according to the International Campaign to Ban Landmines, a coalition of non-governmental organizations, Colombia is not on trackfor a 2021 victory. Bureaucracy has slowed an already slow process, and certain parts of the country are still under control of organized criminals and the National Liberation Army, another paramilitary group that has yet to agree to peace. Evidence exists that fresh mines are still being planted in those areas, which, for now, remain impossible for humanitarian groups and researchers to reach.
If some of the technologies come to fruition in the next couple years, though, Colombia may have a chance of demining the parts of the country that are at peace by 2021. Nor is Colombia the only nation that could benefit from better landmine detecting and deactivating technologies, Cristancho points out. “Everywhere where you have some kind of political or military conflict, they use landmines, and in the worst case, they use IEDs,” he says.
“Will we get there? I don’t know. But we’re doing everything we can to advance science and technology in this country,” Vega says. “At the same time, we’re producing things that may solve other problems tomorrow.”
Source : http://www.pbs.org/wgbh/nova/next/military/demining-colombia/