MICHAEL BERNARD KWESI DARKOH discusses the complex
factors underlying the threat to Africa's drylands.

WITHIN THE LAST DECADE or so, 25 countries in Africa  
have faced drastic food shortages as a result of the 
extended drought.

The reduced capacity for food production has brought a
population of over 200 million people to the verge of
calamity. Some have died of starvation, and among the 
survivors, especially the children and young people,  
many will suffer impaired health for the rest of their 

The international community brought in emergency aid,
both in the form of food supplies and of technical
assistance in rehabilitating drought victims. However,
the drought hazard in Africa can be expected to   
continue, recurring at unpredictable intervals. It 
cannot be overcome by one-time massive injections of
emergency aid. A long-range strategy must be developed
which is capable of being realized under the given   
constraints of these impoverished regions through
sustainable development of their fragile environment.

The droughts and famines that have swept over Africa in
the past and which are likely to strike again are not 
sudden natural disasters. Nor are they simply caused by
lack of rainfall. They are the end-results of a long   
deterioration in the ability of Africa to feed itself,
a decline caused largely by mistakes and
mismanagement both inside and outside the continent. 

As Lloyd Timberlake, author of Africa in Crisis, puts 
it, Africa has  taken too much from its land. It has
overdrawn its environmental accounts,  and the result
for much of the continent has been  environmental   

What Timberlake calls  environmental bankruptcy  has
come about as a result of an intricate process of land
degradation whereby the biological potential of the
continent and its ability to support populations is
severely diminished. Desertification is the term that 
has recently been given to this process. Its main
causes are drought, desiccation and human activities.  
Drought is protracted rainfall failure. Its duration is
usually short-term, one to two years. In ecological
terms, it is a dry period from which an ecosystem often
recovers rapidly after the rains return. Desiccation is
a process of aridification resulting from a dry period
lasting in the order of decades. Human activities   
include overcultivation, overgrazing, deforestation, 
poor irrigation practices and any other inappropriate
land use and human management of ecosystems.

Nowhere in Africa are the effects of desertification
felt as in the arid, semi-arid and sub-humid lands.   
These drylands lie mostly along the fringes of the two
great deserts in the continent the Sahara and the  
Kalahari where the average annual precipitation is    
between 100mm and 600mm and where the ecology is 
largely based on crop and livestock farming activities.

Drylands in Africa, including the hyper-arid deserts,
comprise 1,959 million hectares (ha) or 65% of the
continent and about one-third of the world's drylands. 
One-third of this area is hyper-arid deserts (672
million ha). These are uninhabited, except in oases.
The remaining two-thirds, or 1,287 million ha, comprise
the arid and semi-arid lands (ASAL). Nearly 400 million
people (two-thirds of all Africans) live in the latter.

It has been estimated that 34% of the surface area of
Africa is under the threat of desertification. This is
equivalent to four-fifths of the ASAL areas of Africa.
Desertification affects three principal areas of the
continent, namely, Mediterranean Africa, the
Sudano-Sahelian region and Africa south of the   

In Sub-Saharan Africa, and in particular the ASAL
areas, one of the foremost causes of desertification is
drought. Virtually every year there is drought in some 
part of the ASAL or another. Major droughts, however,
regularly affect large portions of these dry lands. 
Examples include the droughts of 1968-73, 1982-85 and  
1990-92. During each of these droughts many countries  
in the ASAL experienced substantial food shortages.
With each drought cycle dryland degradation increases.
The Sudano-Sahel region has experienced unpredictable
and severe droughts, the most recent of which has
lasted almost 20 years. This is desiccation.

The second and perhaps the most important cause of
environmental degradation in the ASAL is the rapidly
increasing human and animal population pressure,
leading to overexploitation of and intensified stresses
on the natural resources. The human population in
Africa's ASAL has doubled in the past three decades to 
nearly 400 million and continues to expand at a rate of
three percent a year. This means that the ASAL's
natural resources must feed an additional 12 million
people every year, good weather or bad.

This problem of rapidly increasing population pressures
on the fragile and vulnerable soils of Africa's dryland
regions translates into overexploitation of water,   
land, forest and pasture resources through
overcultivation, overgrazing, deforestation and poor
irrigation practices. The resulting erosion and
degradation of productive lands has led to food   

The extent of desertification as revealed by UNEP's
1991 assessment is alarming. About 73% of the total
agriculturally-used dryland in Africa is affected to   
some degree by various forms of land degradation. About
74% of the continent's rangelands, 61% of the rainfed
croplands and 18% of its irrigated lands are already
affected by desertification at a moderate or higher
degree. This land has lost 25% or more of its fertility
and the process is still going on.

The key problem is soil erosion. Soil, the thin layer
of top-soil on which our survival depends, is a
non-renewable resource. For nature to form a layer of
top-soil thick enough to support plant life takes
thousands of years. Through human misuse, the layer can
be destroyed in a few decades, or in a few years. Once
eroded, its loss is permanent. That is desertification.

The continent's precious top-soil is being lost at 
incredible rates. Experts define that any erosion rate 
above 50 tons per square kilometre, 0.5 tons per ha, is
`unusual'. Others say that 10 tons per ha is barely  
`acceptable'. In some parts of the Sudano-Sahelian  
region, soil erosion figures as high as 450 tons per ha
per year are not unusual.

In Ethiopia, an estimated one billion tons of top-soil
is lost each year, as compared to four billion tons in
the United States which has several times Ethiopia's
area of cropland. Observers describe hillside fields 
that have been eroded down to bedrock in the course of
a decade or two.

Throughout most of Sub-Saharan Africa the situation is 
worsening rapidly. Deforestation is accelerating and
continued large increases in rural and urban
populations are likely to further exacerbate this
process over the next few decades.

The exploitation of woodland resources around towns is
leading to deforestation, increased soil erosion and   
sand dune encroachment. The rapidly growing demand for
charcoal among urban populations is leading to severe
desertification within a 40-50km radius of many large 
urban centres in eastern Africa and the Sahel.
According to some reports, rising charcoal consumption
in the Sudanese capital, Khartoum, has caused the area
of charcoal production to shift to the south by an
average of 15-20km a year. The charcoal supplies for
Khartoum now come from as far as 400km away.

The incidence of deforestation resulting from fuelwood
requirements and in association with subsistence and
commercial farming is spreading throughout the   
Sudano-Sahel region. The impact of drought, together
with steadily increasing population pressure on arable
land, has led subsistence farmers to move out of
marginal or depleted lands to extend cultivation into  
forested areas or fragile river basins and mountain   
zones. The encroachment of cultivation on these
vulnerable lands has led to loss of biodiversity and  
accelerated soil erosion, making the people even more
vulnerable to future droughts.

If we look at the countries of eastern and southern
Africa, we find basically similar problems: fragile 
soils being degraded through improper cultivation
practices, fuelwood cutting leading to deforestation,
and overgrazing destroying the ground cover over large

All of these factors combine to leave the land more 
vulnerable to drought and soil erosion. As a result,  
vast tracts of land in Africa's ASAL are being  
transformed into `dust bowls', losing their
productivity and impoverishing their populations.     

The consequences of land degradation are already being
felt in much of Africa. Accelerating desertification is
largely responsible for the fact that many countries in
Africa south of the Sahara are losing the capacity to
feed themselves. Compounded by the rapid population
growth at the rate of three per cent, this is shown by
the fact that between 1970 and 1980 per capita food
production in Sub-Saharan Africa dropped by 11 per   
cent. And that was before these countries felt the full
impact of the last drought. In effect, desertification
is rapidly destroying the natural resource base on
which the future of our nations so much depends.    

Africa provides increasing evidence for linking the
impact of climate and climate change and variability
with the incidence of environmental degradation in arid
and semi-arid lands.

The recent assessment of desertification and drought by
the United Nations Statistical Office (UNSO) shows that
the main threats to sustainability in the Sudano-Sahel
zone are low and erratic rainfall, coupled with soil
erosion by wind, water and the drying up of surface   
water resources and the depletion of ancient
groundwater and salinization of soils. As a result of
the extended drought which peaked during the early
1970s and mid 1980s, Lake Chad at its worst point
contracted to one-third of its normal size. Several
other lakes and rivers throughout the Sudano-Sahel in
western and eastern Africa have fallen to record low
levels and the land has been severely damaged by   
erosion. The UNSO report shows that the effects of  
desiccation on rangeland have been much more serious   
than those of droughts. Many pastoral communities in
the Sudano-Sahel region  have simply ceased to exist as
such after the desiccation of the last 20 years.

Africa also provides evidence of the effect of
progressive land degradation on local climate, and some
recent studies in Botswana shed light on this. At     
Mahalapye in the east and Ghanzi in the west, rises in
mean maximum temperature of the order respectively of
0.3 C and 0.2 C for the initial months preceding the
rainy season (August-October) have been observed for
the period 1921-1946, and rises of 0.7 Celsius and 
1.0 C for the period 1951-70. It is claimed that this
sharp rise in temperature coincided with a great
increase in grazing pressure. At sites in the Western
Kalahari, daily maximum and minimum surface
temperatures over bare ground are reported to increase 
significantly with height above ground level. Cooler
temperatures over bare ground were thought to be due to
the higher albedo or reflectivity over bare sandy soil
rather than over vegetated surface. This thermal
depression effect results in a decreased lifting of air
necessary for precipitation mechanisms to operate, and 
may result in local climatic deterioration.
Desertification in Africa's ASAL, thus, poses a real  
danger of a heat inversion developing over several   
parts of the continent which would lead to a decrease
in rainfall.

Finally, in many African countries desertification is
creating `environmental refugees'. In increasing
numbers, people are forced to abandon their land
because it can no longer sustain them and migrate to
other regions or to urban slums. This problem of
environmental refugees and the widespread
socio-political upheavals in many African countries
today are a foretaste of what we can expect if we do  
not halt desertification.

For some time now, governments and non-governmental    
organizations in the region have been taking measures
at local and national levels to combat desertification.
The UN Plan of Action to Combat Desertification (PACD)
has provided guidelines for many national plans of   
action. But so far, the efforts of these countries have
met with limited success. This limited success in
combating desertification has been attributed to lack
of funds on the one hand and an inequitable
international economic order on the other. While both
are key factors, there are other important issues.  

o  There has been a lack of political will and serious
commitment to combat desertification at national and
international levels.

o  Some anti-desertification programmes have been
fundamentally perceived as technical solutions to      
problems of environmental deterioration and not as   
measures in the solution of problems of human welfare. 
In some countries, the measures are hardly even seen as
integral parts of established national plans for the 
economic and social development of the affected

o  More often than not, the solutions have taken the
form of single set remedies initiated and executed by
particular branches of government departments operating
independently, and there is little or no coordination
which would permit an integrated approach.

o  Even where the right approach is followed, and
adequate plans are put into effect, there is often no
follow-up observation of the impact of the measures.

o  There is a lack of regular monitoring mechanisms and
little is done to involve the local population in
action to combat desertification.

o  Little account is taken of the needs, skills,
experience, wisdom and aspirations of the affected
people. Quite often the measures do not start from a
base that is founded on traditional practice, with all
its well-known adaptations that have given it a
resistance to drought stress.

o  There is no machinery for instruction in land use
practices among local land users.

o  There is a lack of close supervision and control of
grazing to ensure a proper balance between numbers of
livestock and useful plant cover.

o  Quite often, technology is introduced without 
concern for all factors in the environment, that is to
say, in disregard of a proper ecological approach.

Other factors accounting for the limited success are
land tenure and property rights, wars and civil strife,
and misdirected research priorities.

In its evaluation of the PACD, UNEP found that the main
cause of the failure to implement PACD was the failure
of African governments and the donor community to make
desertification a priority issue. Because of scarce
financial resources, and the competing (and often
conflicting) demands on them, African countries are   
unable at present to assign sufficiently high priority
to desertification prevention or control, and have only
to a limited degree included some measures in their
national development plans.

Lack of financial resources from external donors have
also created constraints. Like African governments,
donors prefer projects that will yield quick visible
results that can easily be economically quantified.
UNEP also found that several countries suffering from
desertification in Africa lack adequate national
legislation to stop the human-induced causes of the

Where programmes are developed, they fail because there
is little community participation and support.   
Governments also find it difficult to break through the
traditional bureaucratic syndrome of sectoral planning
and undertake holistic planning.

Agenda 21, the blueprint for action into the 21st
century adopted by the world's governments at the Earth
Summit in Rio de Janeiro in June 1992, did map out   
national strategies for combating desertification: 

o  through intensified soil conservation, afforestation
and reforestation activities;

o  by developing and strengthening integrated
development programmes and integrating them into
national development plans;

o  through drought-preparedness and drought-relief
schemes; and

o  by promoting popular participation.

Will Agenda 21 make governments in Africa and the
international community change and take the issue of   
desertification seriously? It remains to be seen     
whether Agenda 21 will produce the level of action 
needed to address dryland problems which its
predecessor, the PACD, has abysmally failed to produce 
and address in Africa.

Michael Bernard Kwesi Darkoh, a leading authority on
desertification issues, is Professor of Geography at
Kenyatta University.