Malawi's Department of Meteorological Services predicts that the development of a weak La Niña phenomenon in the eastern Pacific Ocean could lead to flooding across the greater part of the country.
Donald Kamdonyo, Director of Meteorological Services, said the appearance of La Niña, which occurs when cooler water wells up to the surface of the eastern central Pacific Ocean, was associated with above normal rainfall over southern Africa. There "is a chance of weak La Niña episode developing over the Pacific Ocean during the 2007/ 2008 rainfall season."
Climate models indicate that in the last quarter of 2007 and the first quarter of 2008, Malawi has a 35 percent chance of above average rainfall, a 40 percent chance of normal rainfall and a 25 percent chance of receiving below average rainfall.
Kamdonyo told IRIN the forecast was based on statistical models using scientifically established relationships between rainfall over southern Africa and sea surface temperatures of the world's oceans.
He said, "We cannot directly attribute this to global warming or climate change because we are ... in a situation where we have already experienced changes in climate."
Lilian Ng'oma, Malawi's Commissioner for Relief and Disaster Preparedness, a government department mandated to oversee humanitarian aid to the victims of natural disasters, said flood-prone areas of the country would be visited and people advised about what actions to take in the event of flooding, such as evacuating their homes and moving to higher ground.
"We are targeting pupils in different schools in this campaign, who will in turn pass on the message to their parents on the effects and dangers of floods," she said.
Farmers in flood-prone areas have resisted moving to higher ground on previous occasions because the land is not as fertile. "We will ask them to move temporarily and not permanently," said Ng'oma.
The relief and disaster department was also coordinating its work with other government departments to achieve a more effective, nationwide response. The Principal Secretary in the Ministry of Water Development and Irrigation, Andrina Mchiela, said plans were already being made "for the provision of clean water and sinking of boreholes in affected areas", should flooding occur.
Geoffrey Luhanga, Controller of Agriculture Services in the Ministry of Agriculture and Food Security, said farmers in flood-prone areas would have to replant seeds if there was flooding, and they were already being advised to do so. Southern Malawi is prone to annual flooding during the rainy season, especially along the Shire River, which flows from Malawi into Mozambique and is a tributary of the Zambezi River.
In January 2007 about 8,000 families in the Chikwawa District were displaced after around 400 villages were flooded along the upper reaches of the Shire River. A further 116 villages were flooded, destroying about 2,600 houses in nearby Nsanje district, through which the Shire River also flows.