Satellites have revolutionised maps

Satellites have revolutionised maps

By Padma Tata
Modern maps have come a long way. Digitised maps can now be produced and transmitted swiftly across large distances through a technology known as geographical information systems. This uses computer hardware and software to analyse and display geographical information, creating digital maps overlaid with a variety of data.

Developing countries tailor the data to their needs, mapping anything from floods or crop stress to disease outbreaks. This is proving a boon to development planners who often find that paper statistics and maps are out of date, inaccurate or poorly maintained.

Health officials in the southern Indian state of Andhra Pradesh have been frustrated for years by difficulties in tracking outbreaks of Japanese encephalitis, the dangerous inflammation of the brain from a viral infection, which can lead to brain damage or death. It took an agonising 16 days, at best, for news of a case in a small village to reach government officials in the state capital of Hyderabad. By the time the health ministry had collated the relevant data and confirmed the cases, an epidemic was upon them.

Information received within few hours
Today, health services can receive information within a few hours. Technicians in Hyderabad receive information on disease cases directly from health workers through the internet, which can then be mapped quickly using these geographical information systems.

The digital mapping tool "helps us to quickly map and identify areas of high incidence, and even update the maps with each new data entry," says K Rajasekhar, a senior technical director at Hyderabad's National Informatics Centre.

Furthermore, the technology can generate a map to show where primary health centres are absent. This proves where new centres are really needed and guards against locations determined at political whim.

In Thailand, maps follow the bird flu epidemic. In 2006, the Asian Institute of Technology in Bangkok launched a project to track fatal strains of the virus, identifying risk zones and the trajectory of any potential outbreak.

Data can map where avian flu is most likely
At a gathering of international experts in Hyderabad in January, the Asian Institute of Technology presented preliminary data showing that countries with temperatures of 25 to 30 degrees Celsius that get around 50 millimetres of rainfall each year were most prone to avian flu. The institute also displayed maps showing how the deadly H5N1 strain of the virus spreads rapidly two months after the first outbreak. This kind of information is crucial in developing best practice for outbreak prevention on farms, says Nitin Tripathi, an institute scientist.

Earlier this year a multidisciplinary research organisation, the French Institute of Pondicherry, launched a project to map areas vulnerable to outbreaks of two mosquito-borne fevers, chikungunya and dengue, in southern India. "We want to study correlations between the type of landscape and vulnerability to disease outbreaks," says Frédéric Borne, head of the institute's geomatics and applied informatics laboratory.

Disaster management too
The same technology is increasingly employed for environmental and disaster management, with satellite images used to monitor floods, hurricanes, droughts, landslides, fires and oil spills. Emergency workers can use these computer tools to prepare maps of disaster zones, visualise disaster scenarios, and develop advanced models and management plans.

In Iran's central Isfahan province and the Prabhani district of central India, remote sensing and geographical information systems help to prepare updated erosion maps. These detail slopes, soil type, drainage patterns and areas where ground water could potentially be replenished, either naturally through rainwater or artificially through aquifers.

Indispensable tools
Basanta Shrestha, head of the Mountain Environment and Natural Resources' Information System in Nepal, says many issues of mountain development such as environmental degradation, deforestation, floods and sharing of water resources, have a strong geographical component. For a small, poor, isolated country, these digital maps "are indispensable tools in analysing environmental issues in mountains," he added.

Indonesia is also using geographical information systems to delineate areas with strong erosion in the Bandung Basin of West Java.

Meanwhile, neighbouring Malaysia is using it to track the haze pollution caused by neighbouring Indonesia's forest fires, and to manage urban planning.

Elsewhere, digital maps are being used to tackle social problems. In Afghanistan, which provides 92% of the world's illicit supply of opium, the United Nations' Office of Drugs and Crime is using the technology to monitor opium crops. And in Delhi, it's helping the government to monitor unauthorised constructions, in real time.

Software licence issues
However, a number of issues block the widespread use of digital mapping technology.
A major problem, according to Kapil Sibal, the Indian science minister, is that the computer hardware and software, data and licensing policies are not available in all countries.
Also, satellite images alone cannot be relied upon and need to be verified with ground surveys.

In 2006, for example, Malaysia found that only 10% of 6000 thermal hotspots indicated in satellite images were real fires. Multiple detection systems are needed to eliminate false signals.

Digital mapping faces further problems
Even with better software and skilled database specialists, digital mapping faces further problems. With private companies, non-governmental organisations and other international players as potential users, governments still hesitate to make the information available in the public domain, citing security reasons.

"For historical reasons, it is widely assumed that Asian economies will not cooperate when sharing GIS (geographical information system) databases," warned Y.B. Dato' Seri Azmi Khalid, Malaysia's minister of natural resources and environment. Some countries have already initiated policy changes.

In 2005, India announced a dual-series policy, putting some digital maps in the public domain whilst retaining others for security agencies. India also plans to set up a National Spatial Database Infrastructure, which will give people access to maps at local community, state, regional and national levels.

But even if maps are shared more widely, there remains the problem of standardising the data. The same set of data often cannot be used by different agencies with different needs. Maps designed for monitoring floods, for example, cannot be overlaid with data to track malaria incidence. Equally important is the cost.

Software still expensive
According to Mangudi Panchapakesn Narayanan, the president of the India's Geospatial Communications Network, the price of hardware has come down but the software is still expensive. He says the poorest countries will be able to afford the technology if the price is halved. "What is needed is government and industry support," he says.

Narayanan believes that an increase in the number of users will also help drive down the cost. Some experts support a drive for an open-source version of digital mapping software, allowing free duplication, changes and redistribution.

But there are also issues involving intellectual property rights. Patents have been granted for some digital maps. According to George Cho, a professor of geoinformatics at the University of Canberra in Australia, "There are still grey areas [regarding] governments' national security concerns, right to privacy of individuals and ethical use of GIS data."

But as geospatial information becomes more important in emergency and disaster management, it will be critical to resolve these issues and ensure that relevant data gets to the countries that need them most. - SciDev.Net

Mapping workshops
Mapping workshops are on offer four times a day at the upcoming national science festival in Grahamstown. But if your interest is more in the satellites than the maps, try Christophe Scicluna, Cambodia-based French science communicator. Scicluna will be running six satellite workshops a day during Sasol SciFest.

Meanwhile, Arvind Gupta, a popular Indian "junk man" educator, is on his way to South Africa to present daily "science through toys" workshops for high school students and teachers at the 11th annual science festival, which kicks off on March 21 and runs until March 27. A full programme is online at www.scifest.org.za