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Kenyan MP and remote sensing expert, Wilbur Ottichilo, argues the time is ripe for using satellites to spot developing African droughts.

The six million square kilometres of the Greater Horn of Africa are home to about 200 million people.

Ecologically and environmentally, the region is highly precarious — more than 60 per cent of it is arid or semi-arid and most countries experience irregular rainfall and frequent droughts.

These conditions often lead to massive crop failures that bring hunger, malnutrition, starvation, mass migration and, in many cases, death.

The region suffers severe food security crises virtually every year, even if the catastrophic and headline-grabbing famines of the mid-1980s in Ethiopia and Sudan have not yet been repeated. For example, in the last two years (2007-2009), Kenya has experienced one of the worst droughts in recent times, resulting in food riots and outright famine.

To predict, monitor and mitigate such disasters we need rapid and continuous data and information gathering. But conventional methods are not effective for the large areas affected and struggle to adapt to global change.

Help from above

Remote sensing can help. Satellites can collect data at global and regional scales rapidly, repetitively and in digital form. Geostationary weather satellites, that sit 35,786 kilometres above the ground and can together see the whole Earth, are particularly useful.

Each satellite collects data every 15 minutes. The information is used to monitor changing weather, compare seasonal trends over time and predict rainfall over large areas, for both the short and long term.

Such data can provide a critical baseline from which future changes can be spotted, and droughts anticipated before they happen. And when used with geographical information systems (GIS) and other geospatial data, such as population density, the information can help measure risk and likely impacts.

Space and GIS technologies are widely used for planning in many parts of the world, yet they have yet to be widely adopted across most of Africa. Politicians remain unaware of the advantages, so countries lack institutional capacity or relevant policies and legislation.

Essentially, top politicians and decision-makers have yet to be convinced that remote sensing is crucial for predicting, and planning for, droughts. Partly this is because few decision-makers have a science background and most do not understand how the technology works.

But the problem is also partly conflicting pressures on limited budgets and the need to solve more tangible problems. Given the choice, most decision-makers will opt to fund a new primary school over a satellite receiving station.

Yet without reliable, systematic early warning systems and better local and national capability to manage disasters, quantifying their socioeconomic and environmental cost, or the benefits early warnings might bring, will remain difficult.

Persuading politicians

Politicians and decision-makers must be sensitised to how important remote sensing can be for disaster management.

Initially, this means researchers must work with members of parliament to demonstrate the power of remote sensing for drought prediction, and to explain how an integrated early warning system would help their local constituents.

Once politicians come on board, they will need to build institutional capacity. This means establishing or strengthening institutions to efficiently manage disasters. Institutions must both use satellite data to predict potential problems and find communication mechanisms to get early warnings out to farmers in the fields.

But there are signs of encouragement on the continent. The Regional Centre for Mapping of Resources for Development (RCMRD), established in 1975 by the UN Economic Commission for Africa, has come into its own in recent years. Based in Nairobi, Kenya, it provides capacity building and advisory services for surveying, mapping, remote sensing and GIS.

Cost and credibility

The main challenge has been convincing countries that satellites are an important source of data. And, until recently, the technology has been generally new and expensive, requiring heavy financial and human investment.

But by 2000, remote sensing and GIS technology had become highly developed, user friendly and fairly cheap. In the last six years, RCMRD has been at the forefront of promoting remote sensing and GIS in Africa, collaborating with NASA to establish a satellite-based disaster early warning system known as SERVIR for Africa.

SERVIR provides real-time information on many disasters, including droughts. The information is made freely available on the Internet.

Many other organisations and institutions in Africa are now also providing satellite data and information for drought and disaster management, including the InterGovernmental Authority on Development's Climate Prediction and Application Centre (ICPAC), in East Africa, the Southern African Development Community, and AGRIMET in West Africa.

We have many of the basic tools required to harness remote sensing for monitoring and mitigating drought.

Equipment and software is cheaper than it has ever been. Satellite data is ready and waiting — two important sources, Meteosat 2nd generation geostationary weather data and SPOT vegetation data, are both free and already come in an easy-to-use format. And since 2004, the European Union has been installing free receiving stations across Africa so that local scientists can access data from a range of satellites directly.

Human capacity is not a major problem either — the RCMRD has been training people to manage remote sensing data for decades.

But for space and GIS technologies to firmly take root in Africa, we must urgently bring politicians on board and help them both build institutional capacity and design relevant policies and legislation.

Wilbur K. Ottichilo is a member of parliament in Kenya's National Assembly and was director general of the Regional Centre for Mapping of Resources for Development from 2000 to 2007.