Above average rainfall across many parts of Southern Africa is prompting concern "about the food security of the affected population in the poorer parts of the sub-region over the coming months," the UN Food and Agriculture Organization (FAO) said in a new report.
"With the rainy season still only halfway through, and with the cyclone season [in the Indian Ocean] due to peak in February, several agricultural areas along the rivers in southern African countries remain at high risk of flooding, including portions of Botswana, Lesotho, Mozambique, Namibia, Zambia, Zimbabwe and South Africa," said the report, published on 7 February.
Cindy Holleman, FAO Regional Emergency Coordinator for Southern Africa, told IRIN that crops were being destroyed by floodwater, and also by excessive rainfall in areas not affected by floods.
Although some usually arid parts had received good rainfall, it was too early to gauge how much the increased food production in these areas would compensate for losses across the region.
"Food insecurity levels are already critical in the affected areas of some of these countries, and floods will only further worsen the ability of poor farmers to cope and feed their families in the coming months," Holleman said.
"Precipitation is likely to exceed 50mm over the northern areas of Mozambique and Zambia, and parts of Angola. Zambia, Malawi and Angola are forecast to continue observing moderate to locally heavy rainfall," the Office for the Coordination of Humanitarian Affairs (OCHA) said in an update on the floods, published on 9 February.
"These same areas are predicted to be affected the following week (15-21 February 2011), but with lower probabilities. Based on this forecast, it is expected that localized flooding will continue to occur across the region, especially in Mozambique and Madagascar."
South Africa experienced riverine flooding that killed 91 people and caused damage estimated by the government at more than US$138 million.
Swaziland's dams are almost full for the first time in five years, and floods have occurred in eastern Botswana as well as the drought-affected areas of southern Madagascar.
OCHA said the Zambezi was still rising, albeit more slowly, and was "expected to reach 6m at Katima Mulilo, [provincial capital of Caprivi]. As at 8 February 2011, the Zambezi River at Katima Mulilo stands at 4.58m, compared to the average level of 1.80m for this time of year."
In parts of southern Africa where there were already poor nutritional levels, the effects of flooding on food security were exacerbated by the regional predominance of the single-harvest maize crop, and FAO was continuing to stress the importance of food producers diversifying the crop regime, she said.
An FAO assessment in Lesotho, a mountainous landlocked country surrounded by South Africa, found that in "some of the flooded areas up to 60 percent of harvests have been lost and over 4,700 livestock, mainly sheep and goats, are dead."
Food production in Zimbabwe and Zambia has so far been affected to a lesser extent, said a recent survey by the US-based Famine Early Warning System Network (FEWSNET), but poor rainfall in some areas during the current wet season meant about 1.7 million people could face food insecurity.
Even though food was available on the market in urban areas, "limited purchasing power continues to restrict the ability of very poor and poor households to access enough food", the network said.
Holleman said the "knock-on effects" of disruptive weather on the food producing season could see higher food prices causing "social unrest" in urban areas such as the Mozambican capital, Maputo, where an estimated 60 percent of the city's about 1.5 million people live in poverty
Riots in Maputo over food prices in early September 2010 killed at least 10 people and injured hundreds of others, after the government instituted a range of price hikes on basic foods and services.
President Armando Guebuza reversed the price hikes by agreeing to subsidies, although economists warned that this would increase inflation, devalue the local currency, and prove unaffordable. Global economic factors have already exerted added pressure, with oil prices breaking the US$100 a barrel level in 2011, and food inflation on the march worldwide.
OCHA noted in its flood update that "23,632 families [in Mozambique] have been affected by floods and around 20,000 hectares of crops damaged," which represents about 0.72 percent of the country’s total planted area.
Madagascar remained vulnerable, with February regarded as the high point of the cyclone season, but so far these weather systems have been absent in 2011. Heavy rains on the Indian Ocean island have been blamed for 15 deaths, and an "estimated 1,625 houses have been damaged, with 105 houses completely destroyed, and around 2,000 people displaced," OCHA said.
Similar weather patterns occurred in 2000, when tropical Cyclone Eline made landfall near Beira, Mozambique, on 22 February, and in concert
with already water-logged fields and high river levels brought wide-scale flooding to the country’s mainly central provinces. More than 700 people were killed and large swathes of crops were destroyed, causing subsequent food insecurity.
"Saturation levels across the region are still very high, meaning that even moderate levels of rainfall could lead to flooding. The development of cyclones over the Indian Ocean is also still a very real possibility, which could cause major damage in Madagascar and along the Mozambican coast, depending on strength and trajectory," OCHA said.
Kenneth Msibi, a water policy and strategy expert at the Southern African Development Community (SADC), based at the regional body’s secretariat in the Botswana capital, Gaborone, told IRIN that since 2000, river management "mitigating" against flooding had vastly improved, as had the proactive evacuation of people living in flood-prone areas.
The Zambezi River, the continent's fourth largest, rises in Zambia and flows through Angola, along the borders of Namibia and Botswana, and into Zambia again, then along the Zimbabwean border and through Mozambique, where it reaches the Indian Ocean about 150km north of the port city of Beira.
The Kariba dam, which straddles Zimbabwe and Zambia, and the Cahora Bassa dam lower downstream in Mozambique, are used to regulate water flows to minimize flood impact, but Msibi said there were other considerations.
OCHA said "the Cahora Bassa dam was releasing about 6,300 m3/s [cubic metres per second]", and "as a result of the increase almost all stations along the Zambezi River are reporting above alert water levels. The current water inflow for this time of year is similar to what was observed in 2007 and 2001, which caused the inundation of large areas."
Water releases from the dams also had to take into account the structural integrity of dam walls to prevent the pressure of the reservoir bursting the barrage, while the operators of hydro-electric facilities had to preserve water for the winter’s dry months to ensure consistent power generation.
Msibi said SADC was currently considering recommendations, including additional instruments and infrastructure developments, to improve data collection on the river’s flow, and management of the water.