Michael Acreman, Freshwater Management Adviser to the
IUCN, Institute of Hydrology, United Kingdom
Water, the Environment, and Population
Water is the lifeblood of our planet. It is fundamental to
the biochemistry of all living organisms. The planet's ecosystems are
linked and maintained by water, and it drives plant growth, provides a
permanent habitat for many species (such as 8,500 species of fish), and
is a breeding ground or temporary home for others, including most of the
worlds 4,200 species of amphibians and reptiles described so far. Water
is also a universal solvent and provides the major pathway for the flow
of sediment, nutrients and pollutants. Through erosion, transportation
and deposition by rivers, glaciers, and icesheets, water shapes the
landscape and through evaporation it drives the energy exchange between
land and the atmosphere, thus controlling the Earth's climate.
Apart from a few minor chemical processes, water is neither created nor
destroyed, it only moves from place to place and changes in quality. The
total amount of water on Earth is 1.4 billion cubic kilometers
(km3), but only around 41,000 km3 circulates
through the hydrological cycle, the remaining being stored for long
periods in the oceans, ice caps and aquifers. Furthermore, the renewal
rate provided by rainfall varies around the world. In the Atacama desert
in southern Peru it almost never rains, whilst 6,000 millimeters (mm) of
rain per year is not uncommon in parts of New Zealand. In any one place
rainfall also varies from year to year.
In the early 1980's the world
witnessed tragic scenes of drought and starvation in the Sahel, but by
August 1988 floods ravaged the same region. Water availability also
varies over a longer time scale. Some 10,000-20,000 years ago, during
glacial phases in high latitudes, rainfall over the current Sahara
desert and Middle East was much higher and percolation of water to
underlying rocks led to the build up of substantial groundwater
resources (Goudie, 1977). However, the recent drier climate in these
regions means that recharge is much reduced and groundwater exploited is
not being replaced at the same rate. Superimposed upon natural climate
cycles are human induced global changes. The consensus is that during
the next century global temperatures will rise by about 0.2ƒ Centigrade
per decade (IPCC, 1996), with some areas exceeding this rate and some
areas cooling. However, it is uncertain how this will affect water
resources. Evaporation is likely to rise, but changes in rainfall
patterns are less easy to predict. However, it is feared that many areas
will become drier and that floods and droughts may become more frequent
and more extreme.
The 20th century has witnessed unprecedented rises in human populations,
from 2.8 billion in 1955 to 5.3 billion in 1990 and is expected to reach
between 7.9 and 9.1 billion by 2025 (Engelman and LeRoy, 1993).
Consequently, human demands for water, for domestic, industrial and
agricultural purposes, are also increasing rapidly. The amount of water
that people use varies, but tends to rise with living standards. In the
United States, each individual typically uses 700 liters per day for
domestic tasks (drinking, cooking and washing), whilst in Senegal, the
average use is 29 liters per day. In general, 100 liters per person per
day is considered a minimum threshold (Falkenmark and Widstrand, 1992)
for personal use. However, when agricultural and industrial uses are
included, countries with less than 1,700 cubic meters (m3)
per person per year (about 4,600 liters per day) are considered to
experience water stress, those with less than 1,000 m3, water
scarcity (World Bank, 1992). Because of the spatial mismatch between
water resources and people, it is predicted that by 2000, (using the
African continent as an example) twelve African countries, with a total
population of approximately 250 million will suffer severe water stress.
A further ten African countries will be similarly stressed by the year
2025 containing some 1.1 billion people, or two thirds of Africa's
population, while four (Kenya, Rwanda, Burundi and Malawi) will be
facing an extreme water crisis (Falkenmark, 1989).
Water for People or the Environment?
With such a water crisis facing many countries, it seems an
immense task just to manage water so that there is enough for people to
drink, let alone enough for agricultural, environmental, and industrial
uses. The situation is often presented as a conflict of competing
demand, as though it was a matter of choice, say, between water for
people, or for wildlife, or for the environment.
The Brundtland Report, Our Common Future, and the United Nations
Conference on Environment and Development (UNCED) in Rio in 1992 seemed
to mark a turning point in modern thinking. A central principle of
Agenda 21 and of Caring for the Earth (IUCN/UNEP/WWF, 1991) is
that the lives of people and the environment are profoundly
inter-linked. Ecological processes keep the planet fit for life,
providing our food, air to breathe, medicines, and much of what we call
"quality of life." The immense biological, chemical and physical
diversity of the Earth form the essential building blocks of the
ecosystem. Thus whilst people need access to water directly to drink,
providing water to the environment means using water indirectly for
people. This concept is so basic that it has permeated all aspects of
water resource management, such as the new water law of South Africa,
whose Ninth Principle states that: "the quantity, quality and
reliability of water required to maintain the ecological functions on
which humans depend shall be reserved so that the human use of water
does not individually or cumulatively compromise the long term
sustainability of aquatic and associated ecosystems."
More attention needs to be given to the role of natural ecosystems in
managing the hydrological cycle and their potential as alternatives to
major engineering works. As an example, well managed headwater
grasslands and forests reduce runoff during wet periods, increase
infiltration to the soil and aquifers and reduce erosion, such as
sustaining flows during drought periods and reducing runoff during
floods. Conserving wetlands in particular, by ensuring that they have
adequate supplies of water to maintain their functioning, can be a
positive benefit to humanity. Many wetlands provide important fisheries,
arable and pasture land, fuelwood and medicines as well as habitats for
wildlife. Some wetlands also perform many important natural hydrological
functions including flooding reduction, water quality improvement (by
removing pollutants) and groundwater recharge. Thus for the millions of
people worldwide who depend directly on wetland resources or benefit
from wetland functions, providing water for the environment and for
people are one and the same.
Principles of Water Management for People and the Environment
In preparation for the IUCN/PRB/US-AID workshop on "Water and
Population Dynamics" which was held at the IUCN's World Conservation
Congress in Montreal, October 1996, I presented some ideas to stimulate
discussion and to provide a framework for examples of water and
population dynamics from around the world. These are presented as a list
in Box 1 and explained more fully below. It is not presupposed that this
is a definitive list, but it nevertheless captures many issues that must
be addressed if water is to be managed sustainably for people and the
environment.
Box 1. Ten Principles of Water Management for People and the Environment |
1. Value water
2. Use water sustainably 3. Develop suitable institutions to manage water 4. Collect and disseminate information 5. Maintain a social and cultural perspective 6. Ensure equitable access to water 7. Use appropriate technology 8. Try to solve causes not symptoms (but accept practical solutions) 9. Take an ecosystem approach 10. Work as multidisciplinary teams |
1. Value Water
To decide on the best use of water, an independent measure of
benefits of various alternative options is required (Barbier et al,
1997). Monetary value is frequently employed as this is how most goods
and services are exchanged in everyday life. The aim is to allocate
water to those uses that yield an overall net gain to society, as
measured in terms of the economic benefits of each use, less its costs.
This is termed economic efficiency. In northern Nigeria, large dams were
constructed on the Hadejia River to feed intensive irrigation, which led
to a reduction in the Hadejia-Nguru wetlands downstream (Hollis et al,
1995). Barbier et al (1991) demonstrated that the economic value of
water when used for intensive irrigation was many times less than its
value for supporting fisheries, agriculture and fuelwood in the wetlands
downstream (Table 1). Consequently, the Nigerian government is now
exploring the potential for releasing water from the dams to restore the
wetlands. Economic valuation thus provided a sound basis for water
management decision making.
Economic valuation is, however, not a panacea for decision-makers facing
difficult choices. One problem is that who actually gains and who loses
from a particular water management scheme is not part of the efficiency
criterion per se. These distributional effects may be very
important since although the scheme may show a substantial net benefit
and would be deemed highly desirable in efficiency terms, the principal
beneficiaries may not necessarily be the ones who bear the burden of the
costs, or suffer any adverse impacts which arise. Kariba dam was the
first of the major dams in Africa, built in 1959 and had a great benefit
to Zambia, as it supplied power for copper mining. However, since no
plans for rural electrification were made, the 50,000 Batongans
displaced by the reservoir bore the burden of the costs, but saw no
benefit (Acreman, 1996).
A further difficulty facing valuation of water is insufficient
information on ecological and hydrological processes, such as the
nutrient recycling or groundwater recharge function of wetlands. If this
information is lacking, considerable investment of time, resources and
effort in further scientific and economic research is required.
Finally, some members of society may argue that certain environmental
systems, such as a tropical rainforest, may have an additional
'preeminent' value in itself beyond what it can provide in terms of
satisfying human preferences, particularly when water management may
lead to the degradation of essential (life-support) functions of
ecosystems, such as nutrient cycling or loss, or decline, of rare
species. From this perspective conserving an ecosystem or species is a
matter of moral obligation rather than efficient or even fair allocation
of the water. Thus, economic values represent just one input into water
management decision-making, alongside other important considerations.
2. Use Water Sustainably
When water resources are used at a rate greater than they are
being replenished, the resource will decline and the usage becomes
unsustainable. In many areas of the world, for example, groundwater is
being extracted from the underlying aquifer more rapidly than it is
being replenished. Around Quetta in Pakistan, where the abstraction rate
is 2.5 cubic meters per second(cumecs), whilst the recharge rate is 2.0
cumecs, the groundwater level is falling at around one meter per year
(Acreman, 1993). Furthermore, the problem is likely to worsen as the
population is growing at seven percent per year (i.e. a doubling in ten
to 11 years). In some areas of Libya, no recharge currently occurs, the
sustainable use rate is zero and thus the water is effectively being
mined. Even where groundwater abstraction might be reduced to equal the
recharge, the groundwater levels have often been lowered to a point
where key ecosystems have been destroyed. For example, pumping of the
aquifer to supply the rapidly expanding population of Amman in Jordan
has led to degradation of the Azraq oasis (Fariz and Hatough-Bouran,
this volume). Similarly, intensive use for irrigated agriculture of the
water from aquifers underlying the upper Guadiana river basin in central
Spain (Figure 1) has resulted in almost complete and irreversible
destruction of the Tablas de Daimiel wetlands (Llamas, 1988). Part of
the problem is that planning has often taken place by deciding first how
much water is needed and then trying to find a source. In contrast, the
opposite process is likely to lead to more sustainable water use, by
first assessing the available water resource and then deciding how best
it can be used.
There are many ways in which water can be used more sustainably:
- Drip irrigation which delivers water to plant roots via a pipe with small holes (Figure 2), is extremely efficient and been used effectively for growing water-hungry crops such as sugar cane in Mauritius (Batchelor and Soopramanien, 1993).
- Charging for water will reduce demand and make investment in drip irrigation technology and repairs to leaking pipes economically attractive. In the Messara valley on Crete, some 15,000 irrigation plots now have individual water meters, demand has been reduced and funds used to improve and extend the infrastructure. New water laws in Morocco mandated the formation of water user associations to collect user fees from landowners to support the modernization of pumps and canal infrastructure (Bennis and Houria, this volume).
- The common practice of discarding the "used" cooking or washing water on to a vegetable garden can be extended such that, after primary treatment (for example, by a natural or constructed wetland), waste water can be used for irrigation.
- Desalinization of sea water is currently expensive and only supplies around 1/1000th of our water supply. However, solar powered desalinization plants may be the answer, especially in hot arid regions, such as west Asia (Gleick, 1993).
- Sewage treatment systems in which water is used to flush waste from individual houses to a central treatment plant requires vast quantities of water. In many countries, such as the UK, consideration is being given to waste treatment at source, which uses little water.
3. Develop Suitable Institutions to Manage Water
Institutions at various levels are essential for equitable
allocation of water. At the global level two initiatives are currently
underway, first the World Water Council, that aims to assess global
water resources and policy issues, and second the Global Water
Partnership, which has proposed coordination of large scale programs on
water and sanitation, agriculture and irrigation. For some international
river basins, a special management authority has been established. OMVS
(Organisation pour la mise en valeur du fleuve SÈnÈgal) has defined a
water sharing agreement for the Senegal River between Mali, Mauritania
and Senegal. This includes water for river navigation, irrigation,
hydropower generation and, currently, artificial flood releases to
maintain the traditional agriculture of the riparian wetlands, although
the best allocation between the uses is hotly disputed (Horowitz and
Salam-Murdock, 1990; Hollis, 1996). Mpande and Tawanda (this volume)
argue for the establishment of a regional water management commission
for the Zambezi basin, which includes parts of eight southern Africa
countries. This is required to avoid future conflicts over water
resources, where the average population growth is three percent per year
(a doubling in 22 years) and the demand for domestic, agricultural and
industrial water use is rising rapidly.
Effective institutions are also required at national, provincial and
local level, to ensure that all stakeholders can contribute to the
decision making process. A good example is provided by the Pongolo River
in northeast South Africa near its borders with Swaziland and Mozambique
(Breuwer et al, 1996), where a dam was constructed in the late
1960s to irrigate agricultural land for white settlers. In the event, no
settlers came to use the irrigation scheme. The dam changed the whole
flooding regime of the river which led to crop failure on a massive
scale downstream. In 1978 a workshop led to a plan for controlled
releases to rehabilitate the indigenous agricultural system and the
wildlife. However, initial releases of water from the dam were made at
the wrong time of the year and crops were either washed away or rotted
(Poultney, 1992). In 1987 the Department of Water Affairs and the tribal
authorities agreed to experiment with community participation. As a
result, water committees were established, representing five user
groups: fishermen, livestock keepers, women, and health workers (both
modern primary health care workers and traditional herbalists and
diviners), and were given the mandate to decide when flood waters should
be released. These committees were very successful at carrying out
people's views and have led to management of the river basin to the
benefit of the floodplain users. This is a unique example of where
floodplain users are participating directly in the decision making
process and influencing development and management of the river basin.
Whatever the level, institutions need well-informed members who have an
appreciation of the wide range of issues facing water resource
allocation. Training is an essential element, but training needs vary
with the type of institution. Professional technical advisors require
formal training courses, for example, on water resource planning and
wetland management, whilst local community representatives may be best
trained with involvement in local activities, such as participatory
rural appraisal or through visits to demonstration projects (see the
example from Tumkur District, India by Kumar et al, this volume).
One factor that may severely limit the effectiveness of community
involvement in the management process is mistrust or misconception their
concerns and aspirations are not recognized or properly understood
(Smith, 1995). The rather nebulous term "general public" is often used
by the managing authority to define everyone else, which implies an "us
and them" attitude. If "general public" is replaced with "local
community," "they" become land owners, resource users and individuals
with a direct and personal association with river, lake or wetland. More
importantly, professionals will wish to see themselves as part of that
community and mutual understanding may become easier to achieve.
4. Collect and Disseminate Information
Effective management of resources can only be achieved if
decisions are based on sound information. Even in a country like the UK,
where there are over 1,000 river flow measurement stations, the quantity
of available water resources is still uncertain and considerable funds
are being invested to develop methods of resource assessment for
ungauged rivers (Gustard et al, 1992). Furthermore, hydrological
measurements on slow flowing or static water bodies, such as fens and
marshes, are very rare (Acreman and Hollis, 1996). In many countries,
not even main rivers are monitored effectively, which means that the
true water resource is largely unknown and effective planning and
management are little more than shots in the dark. Likewise, levels of
water use, such as for irrigation, are not known precisely. Thus, in few
countries is it possible to base demand management strategies on
accurate data. In times of economic difficulty, data collection and
research are often the first activities to be cut. In contrast,
hydrological data collection needs to be expanded to cover more rivers,
wetlands and aquifers, both in terms of water quantity and quality.
Better models are required to make predictions, particularly since our
climate is likely to change substantially over the next 50 years.
Furthermore, tests of models and management strategies are required to
see which are applicable under different circumstances. Forecasting of
floods and droughts requires new initiatives and development of
communication systems, such as the World Hydrological Climate
Observation System, known as WHYCOS, which will collect hydrological
information in real-time via satellite from throughout the world (WMO,
1995).
In many countries hydrological data are collected and analyzed and
presented in hydrological year books (Figure 3). However, these are
often not well distributed and in practice are only available to certain
government departments and their consultants. Information on water
resources and population needs presented in a concise and easily
understandable manner and widely disseminated to a wide range of
government officials, researchers and local communities so that they are
all able to participate in decision making process. Summaries of the
local or regional water resource situation should be supported by
details of water management options and visits to demonstration projects
and other institutions facing similar resource shortages.
Communication and dissemination of information needs careful planning.
Whilst a raw data file on diskette may be appropriate for transferring
information to a university researcher, local communities need to
receive their information through easily understandable brochures,
newspaper articles, radio broadcasts and public meetings. Policy makers
need short summary documents with ample charts and simple tables. Thus a
range of media need to be employed to disseminate the information need
for different actors to play a useful role in discussion and decision
making.
5. Maintain a Social and Cultural Perspective
Water is such a fundamental part of lives and is interwoven into
the fabric of our societies. For example, the Christian faith welcomes
new members through baptism, where water symbolizes cleansing the soul
and nourishing the body. Many Hindus believe the River Ganges is sacred:
a dip in it will purify the soul and scattering the ashes of cremated
body on the water will aid rebirth in a higher existence. Management and
allocation of water are thus particularly sensitive issues. Unlike other
resources such as coal or timber, ownership is not accepted in the same
way, partly because water is dynamic, flowing through the environment
and perceived as "God-given." Proposals to charge money for water supply
are often met with hostile reactions, even though it can be argued that
the costs are related to the infrastructure and its maintenance rather
than the water itself. Thus, although water pricing may be theoretically
a sound demand management strategy, its implementation is frequently not
acceptable.
Water recycling is another notion promoted above. However, some regions
believe that it is not acceptable to reuse water that has passed through
a human body. In many developing countries women and children in
particular walk long distances to collect water. Clearly, providing more
convenient wells improves their well-being. However some water supply
projects in Africa installed taps in houses, which resulted in
depression and other social problems because going out of the house to
collect water and do washing was an important social event where women
would meet and chat.
Rivers, lakes and their wetlands are part of the cultural history of
early people being a central element of mythology, art and religion. The
Marsh Arabs of southern Iraq have lived for centuries on artificial
islands in the marshes at the confluence of the Tigris and Euphrates
rivers. Their lives have been very much in harmony with the wetlands and
they have had a spiritual connection which is somehow different from the
direct use of wetland products for boats building and houses
construction. However, diversion of water upstream has led to
desiccation of the marshes and seriously threatens this 5,000 year old
culture. The Somerset Levels wetlands of the UK are also important for
their cultural heritage. Here fewer people depend directly on the
wetlands for their livelihood, but they are no less a fundamental part
of life for local people. Also people who have moved away from the area
and live in a town hold pleasant memories of life in the wetland.
Because of these strong links to water, it is difficult to derive an
economic value for this use of water, and techniques such as asking
people how much they would need to receive in compensation for
destruction of a wetland are not well received. Thus, whilst scientific
approach to water management has many advantages, decision making needs
to take account of ethical, aesthetic and religious values.
6. Ensure Equitable Access to Water
Water resource statistics are often provided on a per capita
basis. This represents an average across the entire population, giving
the impression of equality in the availability of the resource, i.e.
equal access and equal ability to pay (if charged for). The contrast in
access is strikingly evident in many developing countries. In the city
of Quetta, Pakistan, some rich residents have private boreholes which
they use for filling their swimming pools and washing their cars, whilst
50 meters away the poor take their water from muddy pools. Furthermore,
several studies have shown that the urban poor pay higher prices and
spend proportionally more of their income on water. In Port-au-Prince,
Haiti, the poorest households can spend 20 percent of their income on
water; in Onitsha, Nigeria, the poor pay 18 percent whilst the upper
income households pay two percent. In Jakarta, Indonesia, 32 percent buy
water from street vendors at US$1.5 to US$5.2 per cubic meter, sometimes
paying 25 to 50 times more than the 14 percent of households who receive
water from the municipal system (World Bank, 1993).
In addition, the burden of insufficient water quantity of quality for
domestic use is likely to be borne disproportionately by women and
children. Because they are the primary water collectors, longer
collection times mean that women have less time for agricultural
production and less time for child care. Water is vital to women for
many small scale food processing or craft activities, which are
important sources of income (Serageldin, 1995). Women are also the main
care providers, thus sickness in the family due to contaminated water
impacts them more severely than men.
Problems of access to water and land in the Kafue Flats (Chabwela and
Mumba) are more subtle, but just as critical.
The Kafue and Itezhitezhi dams, which control water availability on the
wetlands, are managed by the Zambian Electricity Supply Corporation to
maximize hydroelectric power output. This has altered the flow regime of
the river, reduced flooding and adversely affecting the fish stocks
available to subsistence producers. Much of the traditional grazing land
that is still flooded has been designated as a national park, thus local
herders have been forced out and now overgraze the remaining areas.
Kumar et al show how access to water in Tumkur
District, India, has been affected by the switch from gravity fed tank
and canal irrigation, from which all farmers benefited, to boreholes
driven by electric pumps which benefit only farmers with sufficient
capital to sink a borehole. The subsidy on electricity for pumps has led
to a vicious spiral of unsustainable pumping leading to lowering of
groundwater levels which has resulted in increased reliance on pumps. As
water is so fundamental to life, inequitable allocation of water is a
sensitive subject. Nizamani et al (this volume) reports how, in 1992, a
local community-based organization (CBO) took the irrigation department
to the human rights court on the basis that corrupt officials were
accepting bribes from wealthy farmers in the head areas to increase
their irrigation flows. This had led to reduced flows in the tail area,
increased salinization of crop and drinking water and migration of
8,000-10,000 people from 38 villages. Although the CBO won the case, not
all of the migrants returned to the area.
Where water resources cross provincial or national borders, downstream
users may be denied access to water by hydrological management upstream.
The Farakka Barrage, constructed in 1974, on the Ganges in India, a few
kilometers upstream of the border with Bangladesh, has reduced flows
downstream by one half (Rashid and Kabir). Dry
season flows are particularly important to flush sediments, sustain
fisheries and prevent sea-water incursion, and their reduction leads to
saline soils and groundwater, affecting some 20 million people. The
Sunderbans mangrove ecosystem, on which some 500,000 people and a unique
ecology depend, is also being degraded as freshwater flows are
diminished.
7. Use Appropriate Technology
Many water resource schemes in developing countries were
conceived, designed and implemented from a developed country view point.
Until the 1970s, one of the main underlying philosophies was the need to
control nature. Technology was seen as the means to bring order to the
vagaries of the world's climate. For example, dams are used to store
water during rainy periods and release it when needed during the dry
season for industry, agriculture or power generation. This is
particularly important on rivers with seasonally varying flows. Climate
extremes, such as floods, were seen as wholly negative and there was
little appreciation of the central role that floods have played for many
centuries in the rural economy of many developing countries. The
inundation of floodplains provides a breeding ground for large numbers
of fish and brings essential moisture and nutrients to the soil,
supporting, for example, gallery forests and essential dry season
grazing for migrant herds. As an alternative to large river engineering
schemes, the Hadejia-Nguru Wetlands Conservation Project in Nigeria, for
example, has promoted improved local water management within the
wetlands, with the construction of small embankments and simple wooden
sluice gates. The wooden gate can be replaced by wire mesh screens to
allow water into fields whilst keeping out fish, which eat the young
rice shoots, until the plants have become established.
This example highlights the need to make use of traditional technology
which has developed over many years, often in concert with the
environment rather than against it. In contrast to many large, modern,
intensive irrigation schemes, that have been shown to be unsustainable,
the Mayan people of Central America developed irrigation canals and
raised fields (chinampas) that sustained their civilization for many
centuries (Barrientos and Fern·ndez, this volume). Small earth dams have
been beneficial in arid areas of Pakistan, encouraging groundwater
recharge (if sited over permeable rocks) and trapping sediment which can
be cultivated in situ or excavated to fertilize surrounding agricultural
land. Throughout west Asia, much water is stored in alluvial cones at
the base of steep impermeable slopes. This has been exploited
traditionally by the excavation of tunnels, from the alluvium downslope
towards the villages or agricultural land, with vertical shafts every
few hundred meters to provide water abstraction points (Figure 4). Many
of these have now fallen into disrepair and replaced by boreholes
directly into deeper aquifers powered by electric pumps, which have
permitted over-exploitation of the groundwater.
Whilst technology has clearly brought benefits to many people, to be
sustainable it must be appropriate in terms of the ability of local
people to maintain the system and appropriate for the environment, as
far as possible working in sympathy with it, rather than just against
it.
8. Try to Solve Causes Not Symptoms
With many environmental, social, health or economic problems, it
is easier to locate and treat the symptoms rather than the cause. As
part of the development of the Senegal River basin the Diama barrage was
built across the river mouth. This allowed its use for irrigation, since
periods of saline water intrusion into the river, which used to occur
during the dry season, were replaced by a regime of continuous
freshwater. This also led to increased survival of snails and mosquitoes
which carry diseases. Before 1987 Rift Valley fever (a mosquito-borne
viral disease) had never been recorded in West Africa and human
intestinal schistosomiasis (an aquatic snail-borne worm parasite
disease) was little recorded. Following construction of the Diama dam
200 human deaths from Rift Valley fever were recorded along with an 80
percent abortion rate among sheep and goats. In 1988, there was a two
percent prevalence rate of schistosomiasis, by 1989 this had risen to 72
percent (Verhoef, 1996). The traditional approach to disease control has
been to spray chemicals to control the mosquitoes and to inoculate local
people. This clearly treats the symptom rather than the cause. However,
the World Health Organization's Panel of Experts on Environmental
Management (PEEM) is now promoting environmental management as a health
control measure which treats the cause. In the case of the Senegal
valley this might mean allowing irrigation areas to dry out or allowing
saline water into the river periodically to mimic the natural system.
In many cases the cause of a problem may be apparent, such as increase
in population putting stress on environmental resources. The River Pang
in central southern England was declared one of the 40 worst affected
rivers in the UK due to pumping of water from the underlying chalk
aquifer that had increased since the mid 1960s for public supply. As a
result the upper reaches of the Pang dried up more frequently and for
longer periods than would normally be expected and the middle and lower
reaches became shallow and sluggish. In 1992 pumping was reduced by
exploiting a new groundwater source and a rise in the groundwater level
occurred (Figure 5). This, combined with high rainfall, resulted in
flows returning to the upper reaches. However, such simple solutions are
not always available and most are fraught with political, cultural or
practical difficulties. It is therefore important to be pragmatic and to
seek reasonable solutions. The restoration of the Azraq Oasis, a
groundwater-fed wetland, in Jordan (Fariz and Hatough-Bouran, this
volume) provides an excellent example. Intensive pumping of the aquifer
to supply the rapidly expanding population of Jordan, and its capital
Amman in particular, led to desiccation of the wetland. The cause of
this problem is the rising population and its increasing demand for
water, for domestic, agricultural and industrial uses. In the long term
this might be addressed by, for example, recycling of water, demand
management, family planning and desalinization. However, immediate
action was required to save the functions and values of the Azraq oasis.
A practical temporary solution was agreed where water is now pumped back
to Azraq, which has revitalized the wetland.
9. Take an Ecosystem Approach
The Dublin Statement (ICWE, 1992), which preceded the UNCED
Conference in Rio, states that "since water sustains all life, effective
management of water resources demands a holistic approach, linking
social and economic development with protection of natural ecosystems."
There is a need to develop a broad-based approach to water management,
with greater emphasis on integrated regional planning and conservation
of critical habitats. The environment is composed of a set of physical,
chemical and biological components, including water, oxygen, plants,
animals, soils, minerals. Each plays an important role either providing
structure, such as rocks, or through interaction with other components,
maintains crucial processes, such as energy flow or nutrient cycling.
Superimposed on this natural environment is the effect of human beings.
There is no place on earth unaffected by human beings, who have had
large scale impacts on the earth's environment ever since agriculture
began thousands of years ago. The ecosystem management approach aims to
integrate all the important physical, chemical and biological components
and processes which interact with social, economic and institutional
factors. This requires integrated management of mountains, drylands,
forests, agriculture, housing, industry, transport, waste disposal,
aquifers, rivers, lakes, wetlands and anything which has an effect on
the environment (Figure 6). The appropriate management scale depends
upon the relative importance of the components in the system. The
fundamental unit for water issues is normally the drainage basin, as
this demarcates a hydrological system, in which components and processes
are linked by water movement. Deforestation of headwater catchments can,
for example, affect water yield and frequency of flooding downstream
(Newson, 1992). Hence the term integrated river basin management has
developed as a broad concept which takes a holistic approach. However,
frequently the underlying aquifer does not coincide with the surface
river basin. Thus, where groundwater plays a significant role, a group
of basins overlying the aquifer may constitute the appropriate unit of
water resource management. For issues where air quality is influential,
such as acid rain, the "airshed" (as opposed to the watershed) will be
more appropriate implying the integrated management of source areas,
which may be industries in the UK, with affected areas in Scandinavia.
An ecosystem approach, through integrated river basin management aims to
make the sustainable use of resources within a river basin. Once the
scientific basis for management options has been defined by professional
staff, the participation of local communities, farmers, industry and
conservation organizations is needed to satisfy the needs of different
interest groups. Successful integrated management frequently begins with
studies of the interactions between various natural components of the
drainage basin and the role of specific ecosystems. N'Djim and Doumbia
(this volume), for example, report on the effects of deforestation
(mainly for fuelwood) and overgrazing of marginal drylands on the
hydrological cycle, reducing the infiltration of rain to the soil and
increasing the severity of droughts. This exemplifies the need to link
land use and hydrogeochemical processes in drainage basin studies.
10. Work as Multidisciplinary Teams
Most river basins contain a variety of landscapes, land uses,
habitats, industry, communities, laws and traditions. Thus,
implementation of a truly integrated ecosystem approach as proposed
above, requires the establishment of interdisciplinary teams including
hydrologists, water engineers, biologists, physicists, soil scientists,
planners, human and animal health experts, ecologists, sociologists,
demographers, legal experts, and agro-foresters. These teams need to
address a wide range of sectoral topics including population dynamics,
water quality modeling, irrigation, health problems, water weeds, fish,
herding, legislation, training, and participatory rural appraisal. In
addition there will be many cross-sectoral issues, such as development
of a geographical information system to overlay various spatial data
sets, equitable allocation of resources, development of community
participation in resource management, establishment and running of
authorities to coordinate planning and management. Conventionally,
different disciplines tend to be specialize in separate sectors, for
example, hydrologists and fisheries experts often belong to different
ministries between which there is little formal contact. Each sector
often has its own agencies and authorities responsible for development,
many of which relate to water issues. Given the interconnection of the
ecosystem, it is critical that inter-sector, interagency collaboration
is established to develop the multidisciplinary team. Indeed, ecosystem
management accepts that no individual or agency can cover all the
different aspects involved. The various agencies should collaborate on
all aspects of planning and implementation of projects, including
problem analysis, project design, data collection, analysis and
modeling, policy development, management and enforcement, monitoring and
evaluation.
Conclusions
The Earth is shared by people and a range of plants and
animals which is so wide that not all species have been, or ever will
be, identified, or their functions understood. Despite the lack of
detailed knowledge, it is clear that each of the physical, biological
and chemical components of the Earth plays an important role in its
structure and function. Furthermore, water is essential to people,
plants and animals alike. Water management has traditionally been
focused on providing enough for people to drink, grow their food and
support their industries. Providing water to the "environment" is often
viewed as a luxury which only rich countries can afford. As the world's
population rises, there will be increasing demand to ensure that direct
supply of water to the human race is given top priority. However, people
cannot live by water alone and require the services of environment's
life support system, which itself needs water to function. Sound water
management should, therefore, focus on the global ecosystem and not as a
conflict against nature to supply water for people. Mutual survival of
people and the environment means that the ten principles of water
management must be followed. Water must be: valued; used sustainably;
administered by suitable institutions; viewed through a social and
cultural perspective; equally accessible to all; developed through the
use of appropriate technology; cared for by treating the causes of
problems and not just their symptoms; managed through an ecosystem
approach; and dealt with by multidisciplinary teams which collect and
disseminate a wide range of information to produce sound decision
making.
References
Acreman, M.C., 1993. Hydrology and the environment. The Lower
Indus and Balochistan. Report to IUCN Pakistan. Gland,
Switzerland: IUCN.
Acreman, M.C., 1996. Environmental effects of hydro-electric power
generation in Africa and the potential for artificial floods. Water and
Environmental Management, v10 n6, 429-435.
Acreman, M.C. and Hollis, G.E., Eds., 1996. Water management and
wetlands in sub-Saharan Africa. Gland, Switzerland: IUCN.
Batchelor, C. and Soopramanien, G.C., 1993. Drip Irrigation Research.
Final report of the MSIRI-IH Drip Irrigation Research Project. IH
Report to Overseas Development Assistance 1/93. Wallingford, UK:
Institute of Hydrology.
Barbier, E.B. Adams, W.M. and Kimmage, K., 1991. Economic Valuation of
Wetland Benefits: the Hadejia-Jama'are Floodplain, Nigeria. London
Environmental Economics Centre Paper DP 91-02. London, UK: International
Institute for Environment and Development.
Barbier, E.B., Acreman, M.C. and Knowler, D., 1997. Economic valuation
of wetlands: a guide for policy makers and planners. Gland, Switzerland:
Ramsar Convention.
Breuwer, C., Poultney, C. and Nyathi, Z., 1996. "Community based
hydrological management of the Phongolo floodplain." In Water and
Wetland Management in Sub-Saharan Africa. Acreman, M.C. and Hollis,
G.E., eds. Gland, Switzerland: IUCN.
Engelman, R. and LeRoy, P., 1993. Sustaining Water-Population and the
Future of Renewable Water Supplies. Washington D.C.: Population Action
International.
Falkenmark, M., 1989. "The massive water scarcity now threatening
Africa: why isn't it being addressed?" Ambio, v18n2.
Falkenmark, M. and Widstrand, C., 1992. "Population and Water Resources:
A Delicate Balance." Population Bulletin v47n3. Washington, D.C.:
Population Reference Bureau.
Goudie, A., 1977 Environmental Change. Oxford, UK: Oxford University
Press.
Gleick, P.H., Ed., 1993. Water in Crisis: A Guide to the World's
Freshwater Resources. New York: Oxford University Press.
Gustard, A., Bullock, A. and Dixon, J.M., 1992. Low Flow Estimation in
the UK. Institute of Hydrology Report 108. Wallingford, UK: Institute of
Hydrology.
Hadejia-Nguru Wetlands Conservation Project/National Institute for
Policy and Strategic Studies, 1993. Proceedings of the Workshop on the
Management of the Water Resources of the Komodugu-Yobe Basin. Kuru,
Nigeria: National Institute Press.
Hollis, G.E., 1996. "Hydrological inputs to management policy for the
Senegal River and its floodplain." In Water and wetland management in
sub-Saharan Africa, eds. Acreman, M.C. and Hollis, G.E. Gland,
Switzerland: IUCN.
Hollis, G.E., Adams, W.M. and Aminu-Kano, M., Eds., 1995. Hadejia-Nguru
Wetlands and Wetland Management in Sub-Saharan Africa. Gland,
Switzerland: IUCN.
Horowitz, M. and Salam-Murdock, 1990. Senegal River Basin Monitoring
Activity Synthesis. Binghamton, New York: Institute for Development
Anthropology.
International Conference on Water and the Environment, 1992. The Dublin
Statement and Record of the Conference. Geneva: World Meteorological
Organization.
IPCC-Inter-Governmental Panel on Climate Change, 1996. Climate Change
1995 - The Science of Climate Change. Cambridge, UK: Cambridge
University Press.
IUCN/UNEP/WWF, 1991. Caring for the Earth - A Strategy for Sustainable
Living. Gland, Switzerland: IUCN.
Llamas, M.R., 1988. "Conflicts between wetland conservation and
groundwater exploitation: two case studies in Spain." Environmental
Geology, v11n3, pp. 241-251.
Poultney, C., 1992. "Water committees take action." ILEIA Newsletter, v1n92, pp. 18-20.
Newson, M.D., 1992. Land, Water and Development-River Basin Systems and
Their Sustainable Management. London: Routledge.
Serageldin, I., 1995. Towards Sustainable Management of Water Resources.
Directions in Development. Washington, DC: The World Bank.
Smith, B.J., 1995. "The Medway River Project: an example of community
participation in integrated river management." In Integrated
River Basin Management, eds. Kirby, C. and White. London: Wiley.
Verhoef, H., 1996. "Health aspects of Sahelian floodplain development."
In Water and Wetland Management in Sub-Saharan Africa, eds.
Acreman, M.C. and Hollis, G.E. Gland, Switzerland: IUCN.
Pearce, F., 1993. "Draining life from Iraq's marshes." New
Scientist, 17 April 1993, pp. 11-12.
World Bank, 1992. World Development Report 1992. New York: Oxford
University Press.
World Bank, 1993. Water Resources Management. Policy
paper. Washington, DC: World Bank.
WMO-World Meteorological Organization, 1995. WYCOS World Climate
Observation System. Geneva: WMO.
Table of Contents | EHN Homepage | AAAS Homepage |
No comments:
Post a Comment