By Maria Caspani

LONDON (AlertNet) - Satellite imagery has become a standard tool for tackling humanitarian crises but thanks to the wider availability now of maps showing base-line information such as roads, bridges and railways, mapping experts are able to create a much more detailed response.

One example of how satellite images are combined with the nitty-gritty of detailed maps is how the United Nations' satellite agency UNOSAT is using Google's MapMaker software.

"MapMaker gives us access to the so-called baseline data over areas where detailed information is usually unavailable," Einar Bjorgo, UNOSAT's head of Rapid Mapping, Applications and User Relations told AlertNet in a telephone interview.

"Accessing this material has always been a major problem in the mapping of crises, especially in developing countries where there is a general lack of detailed maps and data," said Bjorgo.

MapMaker, a free-to-use service launched by Google in June 2008 to respond to a growing demand for mapping data, allows users to add or edit features, such as roads, bridges, schools and more.

Knowing and being able to map details such as which buildings have collapsed during an earthquake, for example, and which roads are still operable becomes vital as it can help aid workers to reach the places where their help is most needed in the shortest possible time.

"As crises happen there is a desperate need to get the best coverage possible in the shortest time," said Bjorgo.

"We want to create a sort of 'on demand' mapping system. Satellite imagery, for example the extent of floods , is combined with the base-line data provided by MapMaker so that roads, bridges, buildings can be mapped."

UNOSAT and Google have been working closely since November 2009 to produce highly detailed maps.

Bjorgo's team has been testing this approach in some of its recent operations in mapping the humanitarian demands after the Haiti earthquake and in monitoring flood affected areas in the Agadez region of Niger.

Most recently the UNOSAT experts have been detailing the extent of a lake in Pakistan that is threatening to burst, a crisis that has already led to the evacuation of thousands of people.

"We are currently following a potential dam burst in Pakistan where we mapped the extent of the flooding of Lake Ataabad," explained Bjorgo.

"We also used Google MapMaker when Vietnam was hit by heavy flooding in 2009 and in more complex emergencies to get information such as road conditions and names of small villages."

A GROWING CRISIS MAPPING COMMUNITY

Bjorgo is keen to broaden the contributor base for providing information to be used in maps when a disaster strikes.

"UNOSAT is now trying to get the whole user community involved," he said.

"Survivors of a quake or a flooding could send information and imagery of what is happening around them via mobile phones, while aid workers could provide data on the number of available food supplies and engineers could track the infrastructure damage," said Bjorgo.

"Humanitarians and people on the ground would then have rapid access to a great number of extremely detailed information. They will know which villages are flooded, which roads have been cut off and which bridges are still standing."

"When Cyclone Nargis hit Myanmar we worked with a number of local people who provided some useful input, but information could come from everyone: aid workers and local authorities as well as from people who are not on the ground."

"It is not a question of handing the job over to the community but certain tasks, especially when it comes to baseline information, could be easily and quickly provided by users."

"The so called humanitarian rapid mapping is delivered at no cost because we have good access to public satellite imagery that is either provided to us for free or is simply available on the internet," added Bjorgo.

The access to geospatial information is normally provided by a vast range of open sources such as Open Street Map (OSM) and MapMaker. However, the Google service has turned out to be very useful because of the quantity and quality of detailed information it can provide to programmes like UNOSAT.

Similar free-to-use services, such as Open Street Map and Google Earth, also have been very useful in the field. Google Earth has been widely embraced by the humanitarian community since its launch in 2005 but a drawback is that many parts of the world are not yet available in high resolution and that some of the available material is outdated.

UNOSAT is a part of the United Nations Institute for Training and Research (UNITAR). It has supported humanitarian agencies and programmes in some 200 disaster response and complex emergency operations since 2003 by working in close cooperation with mapping experts on the ground such as MapAction, CartONG, iMMAP and others.

Reuters AlertNet is not responsible for the content of external websites.