ENVIRONMENT/Geographical
information system
ENVIRONNEMENT / SYSTEME D’INFORMATION GEOGRAPHIQUE
REFLECTIONS ON ENVIRONMENTAL CHANGE AND SUSTAINABLE
AGRICULTURE
IN AREAS OF AUTONOMOUS TRYPANOSOMOSIS CONTROL
QUELQUES REMARQUES SUR
LE CHANGEMENT DE L’ENVIRONNEMENT ET L’AGRICULTURE DURABLE DANS DES ZONES DE
CONTROLE AUTONOME DE LA TRYPANOSOMOSE
David Bourn
Environmental Research Group Oxford Limited
Website: http://ergodd.zoo.ox.ac.uk E-mail: david.bourn@ntlworld.com
Résumé
De graves dégradations de l’environnement dues en partie aux activités
agricoles continuent d’affecter toute l’Afrique.
Beaucoup de pays n’ont ni les moyens ni la volonté d’intégrer les
impératifs écologiques dans leurs politiques de développement agricole et
rural.
Cela s’explique notamment par le fait que les débats relatifs à
l’agriculture durable à l’échelle internationale ont été axés sur les problèmes
écologiques sans véritable participation des Ministères de l’Agriculture.
L’agriculture est généralement considérée comme étant la source du
problème, sans tenir compte du fait que de bonnes pratiques agricoles figurent
aussi parmi les solutions.
Cette communication met en exergue les principaux acteurs du changement de
l’environnement dans les zones infestées par les tsétsé en Afrique et identifie
les principaux facteurs de promotion de l’agriculture durable.
Summary
Serious
environmental degradation, caused at least in part by agricultural activities,
continues apace throughout
Many countries
appear unable, or unwilling, to integrate environmental considerations into
their agricultural and rural development policies.
One reason for this
is that the international debate on sustainable agriculture has concentrated on
environmental issues, with which many ministries of agriculture are not fully
engaged.
Agriculture is
often presented as a significant part of the problem, with little regard for
good agricultural practices that are part of the solution.
This paper
highlights the main drivers of environmental change in tsetse-controlled areas
of
Introduction
Two years ago at
the previous ISCTRC meeting in
Last year, I was
fortunate enough to return to western Ethiopia, 25 years after my first field
studies there in 1976/77 (Bourn and Scott, 1978), to work with the national
component of the East African regional programme to promote Farming in Tsetse
Controlled Areas (FITCA).
The FITCA programme includes
This presentation
is based on my work with FITCA-Ethiopia (Bourn, 2002) and that of two
colleagues: Bruce King, remote sensing and land use planning specialist (King,
2002); and Chris Rhodes, forestry resource and community management specialist
(
Environmental Change
All natural
ecosystems and environments are dynamic entities, varying from day to night,
from day to day, from month to month, from season to season, from year to year,
and over much longer periods, driven by global, lunar and solar cycles, and
various atmospheric, oceanic and geological processes (Goudie, 2001).
In addition to
these natural phenomena, human activities also have many profound impacts on
the environment, which maybe of local, national, regional or global
significance, relating to changes in plants, animals, soils, water, landscapes
and the atmosphere. Examples include: the use of fire to clear land and for
hunting; the construction of roads to improve access and facilitate the
movement of people, produce and trade; agricultural expansion, deforestation
and loss of biodiversity; urbanisation, industrialisation and pollution; green
house gas emissions leading to global warming, climate change and rising sea
levels.
It is important to
understand the causes and consequences of environmental change, so that
appropriate strategies can be devised and implemented to promote sustainable
practices and discourage harmful ones. This is especially so with the expansion
of farming, natural resource management and the promotion of sustainable
agriculture and rural development.
Sustainable
Agriculture and Rural Development
The concept of
Sustainable Agriculture and Rural Development (SARD) encompasses a broad range
of human activities, economic sectors and administrative responsibilities, and
is inherently interdisciplinary in nature, involving not just agriculture, but
also education, energy, health, water, natural resource management and
conservation. Agriculture and rural development are deemed to be sustainable
when they are “ecologically sound, economically viable, socially just,
culturally appropriate, humane and based on a holistic scientific approach” (http://www.fao.org/wssd/-SARD/SARD1_en.htm).
Volume one of the
FAO trainer’s manual on "Sustainability issues in agricultural and rural
development policies" (FAO, 1995) defines SARD as a process that:
·
Ensures that the
basic nutritional requirements of present and future generations are met, both
qualitatively and quantitatively, whilst at the same time providing a variety
of other agricultural products;
·
Provides durable
employment, sufficient income, and decent living and working conditions for all
those engaged in agricultural production;
·
Maintains and,
where possible, enhances the productive capacity of the natural resource base
as a whole, and the regenerative capacity of renewable resources, without
disrupting the functioning of basic ecological cycles and natural balances,
destroying the socio-cultural attributes of rural communities, or contaminating
the environment;
·
Reduces the
vulnerability of the agricultural sector to adverse natural and socio-economic
factors and other risks, and strengthens self-reliance.
In short, SARD is
a complex, long-term process, involving many players at all levels of society
from farmer to politician.
Environmental
Change in South-western
The main drivers
of environmental change in south-western
Human
Population Growth and Distribution
When
Most Ethiopians
live in the highlands, where the climate is cooler and rainfall is greater.
With population growth, there is keen competition for land resources, and
agricultural settlement has been expanding for many decades, both in the
highlands, where land suitable for farming is still available, but increasingly
into peripheral slopes and lowlands (Figure
1b).
Figure 1: Human Population Growth and
Distribution
|
a) Growth
|
b)
Distribution
|
Sources: United
Nations (2003) and FAO et al. (2001)
Resettlement
and Migration
There has been a
very substantial movement and redistribution of people in Ethiopia over the
past few decades, arising from a combination of factors relating to recurrent
droughts and famines, and both government organised and spontaneous
resettlement. Voluntary resettlement, or migration to less densely populated
areas with agricultural potential continues apace today and is a cause of
mounting social and political discontent.
During the late seventies and early eighties, some
320,000 families from drought-stricken regions in northern
Figure 2: Resettlement in Areas of Trypanosomosis Risk
Source: MOA (1984).
Migration
The scale and extent
of population movement and redistribution of people during the seventies and
eighties is reflected in the 1994 census, in which some 7 million people or
14.1% of the population, excluding nomadic Afars and Somalis, were classified
as migrants. For people in rural areas, migrants were defined as those who had
come from any urban area, or who had moved from a rural area in another wereda.
For people in urban areas, migrants were defined as those who came from any
rural area, or who had come from any other town.
Oromiya, Amhara,
Southern Nations, Nationalities and Peoples (SNNP) and
Figure 3: Number of
Migrants in Regional States – 1994 Census
Source: CSA
(1998).
Agricultural
Expansion
Land Use Change in the
King (2002) examined changes in land cover/land use in
the Upper Dhidessa catchment over the past three decades, comparing 1973 aerial
photography with 2001 LANDSAT imagery. Six east-west strip transects of aerial
photographs provided coverage of highlands, valley slopes and the valley floor:
one strip was five kilometres north of Bedele town; one was at the same
latitude of Bedele town; one was at the latitude of Gechi town; and the other
three were centred on northings: 906000, 895500 and 892000. Northern, central
and southern portions of each strip of aerial photographs was sampled at
one-kilometre intervals to provide a total of 531 sample points for comparative
land cover assessment. Land cover changes in the
Figure 4.
Table1:
|
|
1973 –
Percentage Cover |
|
|||||||
|
2001 |
|
|
|
Scrubland |
Grassland |
Marsh |
River |
Cultivation |
Total in 2001 |
|
|
21.1 |
|
0.4 |
|
|
|
|
2.4 |
23.9 |
|
|
|
7.7 |
|
|
|
|
|
|
7.7 |
|
|
|
|
10.5 |
|
|
|
|
0.6 |
11.1 |
|
Scrubland |
1.1 |
0.2 |
|
2.8 |
0.6 |
|
|
3.0 |
7.7 |
|
Grassland |
|
|
|
0.2 |
11.5 |
|
|
0.6 |
12.2 |
|
Marsh |
|
|
|
|
|
0.8 |
|
|
0.8 |
|
River |
|
|
|
|
0.2 |
|
0.4 |
|
0.6 |
|
Cultivation |
4.3 |
|
4.7 |
0.6 |
0.6 |
|
|
25.8 |
36.0 |
|
Total in 1973 |
26.6 |
7.9 |
15.6 |
3.6 |
12.8 |
0.8 |
0.4 |
32.4 |
100.0 |
Source: Derived from King (2002).
Cultivation increased by 11.1%, from 32.4% of the land
area in 1973 to 36.0% in 2001, largely at the expense of woodland and forest,
with a significantly higher proportion of woodland (30%) being converted to
cultivation than forest (16.2%). The increase in shrubland from 3.6% to 7.7% is
indicative of an expansion of fallow land.
Figure 4: Land Cover Change in the
Montane forest cover, excluding riverine forest,
declined by 20.3%, from 26.6% in 1973 to 21.1% in 2001. This reduction in
natural forest cover was offset to some extent by the establishment of new
forest plantations mainly of exotic pines (indicated in the table by change
from cultivation and woodland to forest), resulting in a net overall forest
loss of 10.2%. Coffee is a major cash crop in the region and much of the
montane forest is under-planted with coffee bushes, which require shade. Visual
comparison of the aerial photography and satellite imagery indicated that many
small patches of forest had disappeared, while larger plantations have been
created.
Figure 2