Search!

Web envkerala.blogspot.com

Wednesday, April 28, 2010

Sensor devices to predict freak weather

When the town of Cockermouth, Cumbria, northern England, was hit by floods late last year, the freak weather led to deaths and serious injuries, and caused huge damage to thousands of homes and businesses. People from all around the U.K. watched the disaster and called for greater prioritisation of flood defences.

Now, a team of scientists from Southampton University has stepped up to the challenge. Led by Dr Kirk Martinez, a senior lecturer at the university's school of electronics and computer science, the group has created a new sensor device that can help to reduce the unpredictable factor of flash flooding, as well as making other geographical phenomena such as landslides much easier to forecast.

Under glaciers

The technology was developed in 2003, when Martinez began working on a sensor probe that was placed under glaciers to measure climate change. Scientists, Martinez says, “weren't making the most of all the newly available technology”. He adds: “Most research involved trying to insert sensors on a long wire into the ice. The wires tended to break a lot and the researchers had to regularly go out to the site with a laptop to download all the data. I thought there had to be a way of using wireless technology to develop a new measuring technique.” There was: Martinez was able to design small, fist-sized wireless glacier probes, which have a small, low-power computer and radio inside that enables them to regularly take, store and send measurements to a web server accessible from anywhere in the world.

After developing the probes, the researchers used a jet-powered steam “drill” to position the sensors 70 metres deep at various positions in the Skalafellsjokull glacier in Iceland — part of the largest ice cap in Europe.

They were set to record temperature, pressure, movement and the quantity of water in their surroundings to help scientists get an accurate picture of glacial behaviour and predict future movements.

Now, the probes are still in place and able to “talk” to each other, so if a range of readings have been the same for a period of time, some of the devices hibernate to save power. If conditions begin to change, one of the probes “wakes up” the rest of them.

The success of the pilot led Martinez to think bigger. “Initially, it was very difficult to develop the probes,” he explains. “No one had done it before, so we had to design several versions of everything, from the programmes and electronics to the waterproof cases, before we perfected them enough to venture out to other areas. But once they were in place and working, they sent through data reliably and usefully.

“In Iceland, they have already shown us interesting things, like the fact that the glacier began to warm up in February, even though the land on top of it was still very wintry. So we thought there would be other uses for these sensors.” Martinez took the Southampton-designed probes to the Los Laureles Canyon in Mexico, to see if they would collect data that could help to understand landslides as well as studying melting ice caps.

“The canyon area has no proper drainage system, and very poor-quality housing that faces massive flooding problems,” he says. “The streets are not paved and when water flows, it picks up sediment and becomes quite aggressive. So we put our probes in place to measure the ground's tilt, how moist it is, the temperature, and the crushing pressure, to help local scientists prevent landslides.

The probes measure every 10 minutes. Put together with meteorological predictions for rainfall and storms, the data can show how and why things are moving, and indicate the start of a landslide.

It means that the local experts are receiving regular, accurate data and are working on preventative slope management.”

Martinez and his fellow researchers are now looking at ways to make the sensors cheap and easy to install. “At the moment, the probes are handmade so they cost up to GBP200 each, but this could be cut a lot with mass production,” Martinez says.

Non-profit basis

“We're producing them on a non-profit basis right now, but we see environmental monitoring companies buying them to help with their contracts, as well as researchers who want to measure things in remote areas.”

Anticipating floods In the future, Martinez believes the sensors could be used around the world, from flood - monitoring in Cockermouth to landslide — prediction in South America and Asia. “In Britain, they could have a huge impact on how we anticipate flooding.

The sensors' data could not only be used by local environment agencies to trigger an evacuation, but also be directed to a website, so people facing coastal erosion or flooding could check the safety of their homes.

“The exciting thing is that the probes don't need a huge chunk of concrete or a power station to get them to run, they're small, and contain batteries that run for many years.”

Common man benefits

Although they were conceived to fulfil a need of recording data in hard-to-reach environments, Martinez believes one day individual homeowners could buy the sensors to check things such as how fast cliffs are receding, as well as water-monitoring to help people in places like Cockermouth to prepare in advance for flash floods.

“Climate change is happening and we need the combined efforts of measuring what's happening with efforts to prevent it,” Martinez says.

“It's a great time to be working in this field — the technology is ripe to make a huge difference.” — © Guardian Newspapers Limited, 2010

Source: Thursday, Apr 22, 2010

No comments: