Droughts are common in the Kunene River basin, and a particularly devastating in the Lower Kunene where water resources are scarce. Variable and erratic rainfall means that the rainy season often does not start when expected and can be episodic, with an entire season’s rainfall occurring in the space of a few days, and due to the nature of the basin, rapidly running through the steep Upper and Lower Kunene and out to the sea.
In the Lower Kunene, where the river is the only perennial water source, cattle herding communities are particularly vulnerable to even very slight changes in water availability. In the last 10 years, two serious droughts have hit the region (in 2003 and 2007-2008), with hundreds of cattle dying and severe impacts on these communities.
Drought also has an impact on wildlife within the basin.
Source: © Ostby 2007 www.pgoimages.com
( click to enlarge )
The drought of 1991–92 was the most severe in recent history, affecting the entire southern Africa region including the Kunene River basin. Although there are strong indications that drought occurs cyclically in southern Africa, it is not yet possible to predict them with a high degree of certainty. Scientists have discovered a relationship between the El Niño Southern Oscillation (ENSO) and drought in southern Africa, but the correlation is not strong. In terms of hydrological drought, a mixed positive and negative correlation between the warm ENSO events and the quarterly seasonal river runoff in Southern African Rivers has been reported (Alemaw and Chaoka 2006).