Africa: Water deficits to recede in southern Africa; surpluses in Tanzania

20 December 2017

THE BIG PICTURE

The 12-month forecast (above) indicates severe to extreme water deficits across much of northern Africa with exceptional deficits in the northwest, including much of Mauritania as well as pockets in Algeria and Libya. Intense deficits are also forecast for southwest Burkina Faso into Ghana, along the Red Sea in Sudan, southern Cameroon, Equatorial Guinea, and Gabon.

Severe deficits are forecast for eastern Central African Republic into northern Democratic Republic of the Congo. Deficits in southern Africa are expected to be mild to moderate, and deficits of slightly greater severity are forecast for the Horn of Africa.

Surpluses are predicted for southeastern Sudan into South Sudan, northwestern Kenya, western and southeastern Tanzania, and along the border of Cameroon and Central African Republic.

IMPACTS
South Africa’s 2018 wine-grape harvest is expected to be the smallest in over a decade due to this year’s drought, which caused most vineyards’ water supplies to be cut by 40 to 60 percent. The majority of the vineyards are in Western Cape province where drought conditions have been especially persistent. South Africa is the world's seventh biggest wine producer.

The most recent negotiations between Egypt, Sudan and Ethiopia over the Grand Ethiopian Renaissance Dam failed last month, increasing regional tension and anxiety over water supplies from the Nile River. A technical impact assessment was completed in November but ministers from the three countries hold conflicting interpretations of the results. Egypt is currently under the water poverty line, with renewable water resources per capita of 560 cubic meters compared to 1,000 cubic meters internationally, and about 97 percent of Egypt’s total water needs are met by its share of the Nile. Egypt recently announced plans to build the world’s largest desalination plant to supplement its water sources, though this additional source is not expected to solve the water crisis after the construction of the Renaissance dam.

Government and agriculture officials in Uganda are promoting “super beans”, a variety bred via artificial selection to mature rapidly and produce high yields under drought conditions. The United Nations Food and Agriculture Organization recently contracted a commercial producer to supply 21 tons of the bean called NABE15 to South Sudanese refugees, a testament to its success. Researchers are working to evolve or genetically edit this bean into a “super super bean” which has the ideal trait combination of high-yields, early-maturation, drought-tolerance, pest-tolerance, and high nutrition.

FORECAST BREAKDOWN
The 3-month maps (below) show the evolving conditions in more detail.

The near-term forecast through February indicates continued improvement in water conditions in southern Africa as exceptional deficits nearly disappear and primarily mild to moderate deficits emerge. Deficits in Lesotho, however, are expected to be intense. Deficits are forecast across most of Africa’s northern half with pockets of exceptional deficits in western Mauritania trailing down through Guinea-Bissau, scattered around the Gulf of Guinea, in small pockets across the southern Sahara, and a large pocket in southeastern Ethiopia.

Blues and greens on the map call attention to surpluses of varying severity including from southern Sudan through eastern South Sudan and into western Ethiopia, trailing south along the Albert Nile and the Victoria Nile, in central Kenya, northwestern and eastern Tanzania, northeastern Mozambique, and pockets of Madagascar. Surpluses are also forecast for western Democratic Republic of the Congo and from western Central African Republic into Cameroon.

From March through May widespread water deficits reaching exceptional severity are forecast to emerge in central Mali; most of Niger into Chad; Libya; Egypt; and northern Sudan, along with moderate to severe deficits elsewhere across northern Africa. Aforementioned surpluses are forecast to recede overall but will continue to emerge in southern Sudan into eastern South Sudan and in Tanzania. Water conditions in the Horn of Africa are expected to return to near-normal and moderate deficits are forecast in DRC, Namibia, and Zimbabwe.

The forecast for the final quarter – June through August 2018 – indicates conditions similar to those forecast for the preceding three months but with the addition of widespread surpluses in Ethiopia.

(It should be noted that forecast skill declines with longer lead times.)

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.