MIT designs low-tech flood alarm
SANTA ROSA DE AGUAN, Honduras -- Crumbling concrete walls poke up through the sand in this impoverished Honduran fishing community, reminders of Hurricane Mitch's murderous sweep across Central America in October 1998.
The storm, which killed nearly 10,000 people and left more than a million homeless -- most of them in Honduras -- taught the country a lesson: It pays to be prepared.
Since then, the Honduran government has dramatically improved its disaster capabilities, including working with international aid organizations to install more than 60 stream gauges to detect when river levels get dangerously high.
But the system, which operates via satellite and is costly to maintain, is plagued with technical problems and regularly interrupted by vandalism.
And a shortage of sensors in some major waterways, such as the 115-mile long Aguan River in the country's north, has left hundreds of communities like Santa Rosa de Aguan at risk. The village's 1,200 residents are crowded atop a slip of sandbar between the Caribbean Sea and the Aguan River, with little to protect them from the next major hurricane.
Since January 2004, however, students from the Massachusetts Institute of Technology have been working on an early flood warning system for the Aguan River that they say would take over where the government's sensors leave off -- at a fraction of the cost.
''We're just trying to see if we can make it simpler and easier, so [we] can save lives," said Elizabeth Basha, a graduate student in electrical engineering and computer science at MIT, who is leading the project.
Called the FloodSafe Early Warning System, the project uses cheap automatic radios to transmit information from flood-gauge sensors inside the river. If water levels get dangerously high, the system will communicate with radios in local communities, which will trigger an alarm. The radios will also send the information to a central processing office in the nearest big town, Tocoa.
The total cost of each sensor system will be about $2,000, compared with $20,000 for the satellite-transmitting systems, according to Basha. Their eventual goal is to install five to seven of them along the river.
And unlike the satellite systems, which rely on US-trained technicians sent from Tegucigalpa, the capital, the radio systems can be repaired locally.
The students are working with a nongovernmental organization in Tocoa, the San Alonso Rodriguez Technical Center, which won a $380,000 grant from the European Union to help local communities prepare for natural disasters.
The need for emergency coordination became clear during Hurricane Mitch.
''Nobody told us the storm was coming until the water was already up to our necks," said Ezequiel Castillo, a 53-year-old fisherman from Santa Rosa. He and his family barely escaped with their lives after the floodwaters devoured their concrete house, along with 40 other houses in the community. On the other side of the river, 40 residents were swept to their deaths.
Today, there is one shelter on higher ground near Santa Rosa, but to be safe, most residents would need a day's notice to canoe across the river and reach an inland city, two hours' drive by bus.
The roughly 10,000 people living within the flood zone currently rely on volunteers, who manually check the river levels and alert authorities when the water gets too high. But residents don't consistently check the river at night, when most tropical rains occur.
''The key is to eliminate the human intermediaries," said Gines Suarez, a Spanish geologist who heads the local nongovernmental group. ''The radios will sound the alarm, whether there is a person checking the river or not."
To cut costs, the students have created a stripped-down version of an automated radio. They have also designed the motherboards, which process information from the pressure gauges in the river and then transmit it by radio. Because of a lack of reliable charts of the river, they have conducted their own geological mapping during several trips to Honduras. In addition, the entire system, including the 20-foot radio towers, has to be made hurricane- and vandalism-proof.
While the students initially hoped to finish the project by August 2004, they now estimate it will take until August 2006 to have the first test equipment in place and another year to refine the system. If the project works, it could be applied in flood zones throughout the Third World.
Not everyone believes the system will be an improvement on existing technology.
''I've seen students get involved, and it's not an easy task," said Phil Turnipseed, a hydrologist with the United States Geological Survey, who was part of a team that installed 37 stream gauge sensors in Honduras after Hurricane Mitch. He said that the US government had been using radio-powered flood warning systems for more than 50 years but that the newer satellite transmission systems had proved more reliable. Radio towers can get blown down in storms, and all systems, whether radio or satellite, are hard to maintain, Turnipseed said. ''You can't just drop it in the river and leave it there. You have to maintain it, and that's always the hard part." The students are somewhat naive, he said, to think they can devise a better system than the US government engineers have been able to develop over more than 100 years.
Basha is unfazed. ''We're not trying to be super innovative," she said, in a telephone interview from MIT. ''We're trying to solve a problem." She argued that the radios make more sense than satellite systems in a poor country that lacks the infrastructure of the United States.
''With just $30,000 or $40,000 we could have automatic warning systems in all the communities," Suarez, the local project coordinator, said as he paddled a canoe across the river to Santa Rosa. ''Imagine all the lives we could save."
