CLIMATE AND DROUGHT
Year to year rainfall variability is high in the basin countries with the 1970s
being relatively wet while the period 1980-90 have been relatively dry.
Drought is the single most crucial natural disaster that affects the Zambezi Basin.
Research shows that droughts occur every 10-15 years in the basin countries. Since the
turn of the 20th century, eight spells of more or less than nine years have alternated
with similar periods of rainfall that is below normal. These spells, however, have not
always occurred at exactly the same time nor have they affected all countries equally,
which make the trends difficult to follow.
The droughts of the 1980s and 1990s have had a marked negative impact on the Zambezi
Basin states. For example, the lake level at Kariba on the Zambezi River dropped from
487.5m amsl in 1981 (maximum retention level: 488m amsl) to 475.9m amsl (minimum retention
level: 475.5m amsl) in 1992, reflecting a drop of 11.6 metres of water within a decade.
With regard to water availability and hydroelectric power generation, the severe droughts
of 1991-92 and 1994-95 had near-disaster consequences in some of the basin countries.
The period between 1985-95 was disastrous for many rural communities, especially in
Mozambique, southern Zambia and Zimbabwe. Boreholes dried up, making it impossible to grow
crops or maintain livestock, and forced women and children to walk long distances to
collect water for their families' needs. The 1991-92 drought hit particularly hard,
putting more than 18 million people in 10 countries of the SADC region at risk of
starvation. A WWF report adds that, "...urban dwellers were also affected. Water
supplies in Zimbabwe's capital, Harare, sank to alarmingly low levels during 1995 and
power shortages became commonplace. By October 1995, the Kariba Dam, which produces most
of the country's electricity, was running at only 14 percent capacity".
Since the 1991-92 drought that wreaked havoc in most economies of southern Africa,
recovery has been rather slow. After a short respite during the 1992-93 rainy season,
there has been a virtual persistence of droughts in sympathy with El Niņo/Southern
Oscillation (ENSO). For instance, there was a 17 percent fall in maize harvests in 1993-94
season compared to the 1992-93 season, as most countries in the region suffered a
climatically unfavourable growing season. Several rainfall deficits over most of the
sub-region resulted in extensive crop failures in southern Zambia and parts of Zimbabwe.
Only the abundant rains of 1995-96 averted an energy and agricultural crisis for Zambia
and Zimbabwe.
Climate change
According to the World Wide Fund for Nature (WWF), there are indications of climate
change in southern Africa. WWF states that global warming is already affecting much of
southern Africa. Records from the countries that make up SADC reveal that temperatures
have risen by over 0.5°C over the past 100 years, with the last decade being the warmest
and driest ever. Over the past 20 years, there has been noticeably less rainfall, and
drought has become an increasingly serious threat. These disturbing changes are happening
despite the fact that Africa has contributed little to the build-up of greenhouse gases in
the atmosphere.
Projections are that southern Africa will be affected by global warming in both summer
and winter, that rainfall may diminish in certain areas, and that soil moisture will
probably decrease more generally with doubling of carbon dioxide.
Top
Previous:
Poverty
Table Of Contents