Download Scenarios for agricultural water demand

Millennium target
to halve the proportion of people lacking access to safe drinking water by 2015,
together with a complementary target on sanitation
 Proportion of urban population with access to improved sanitation;
 Proportion of population (urban and rural) with sustainable access to an
improved water source.
By 2015, reduce by half the proportion of people without sustainable access
to safe drinking water
One billion people lack access to safe drinking water, 2.4 billion to adequate
sanitation. To achieve this target, an additional 1.5 billion people will require
access to some form of improved water supply by 2015, that is an additional 100
million people each year (or 274,000/day) until 2015.
The main indicators for progress towards this goal are:
- Proportion of population (urban and rural) with sustainable access to an
improved water source.
Challenges
Meeting Basic Needs
Having access to safe and sufficient water and sanitation are now recognized as
basic human rights. Being able to wash one's hands and drink clean water can
have a major impact on family hygiene and health. Women play an especially
important role in this process. Because people who are poor are most likely to
get sick, and ill health perpetuates poverty, it triggers a vicious cycle that
hampers economic and social development.
Protecting Ecosystems
The possible negative impact of human activity on the environment must be
considered when managing water resources in a sustainable way. It is not
enough to draw water from nature for use in agriculture, industry, and everyday
life without also taking account of nature's needs. Animals and plants,
landscapes and wetlands need clean water too. Wastewater must be recycled so
that pollution is minimized. Special areas like estuaries, which play an important
part in supporting the delicate and complex food chain of many birds and fish,
may require total protection. Human beings must learn to respect the resource
base on which life ultimately depends and to see land and water as two sides of
the same coin. For this reason, decisions should be taken at river basin level,
Water and Cities
By 2030, over 60% (nearly 5 billion people) of the world's population will be
living in urban areas. As a result, competing demands from domestic,
commercial, industrial and peri-urban agriculture are putting enormous pressure
on freshwater resources. In their bid to meet soaring demand, cities are going
deeper into ground water sources and farther to surface water sources, at costs
- including environmental costs - which are clearly unsustainable. Cities also face
the challenge of securing access to safe water for the urban poor, and of cutting
down on wasteful and illegal uses. The urban water crisis can only be met by
changes in management and governance that lead to more sustainable use of
the shared resource.
Securing the Food Supply
The challenge here is to increase food production and security by getting 'more
crop per drop', while also devising ways to ensure a more equitable allocation of
water for food production. Since about 80% of the world's water is used for
irrigation, even small changes in the way crops are planted, watered and
harvested can make a big difference. Better ways to enhance the productivity of
rainfed agriculture must also be developed. Poor populations are the most
vulnerable, and the strain will only increase in the face of demographic pressure.
Water and Industry
Industry is both a major user of water resources and a major contributor to
economic and social development. To move towards sustainability, industries
must be assured of having an adequate supply of water. In return, industries
should undertake to see that water used in industrial processes is used
efficiently and not returned to nature as untreated waste that pollutes the
environment. Technology is important for recycling of water, and a variety of
economic and legislative measures can also provide incentives for responsible
management.
Water and Energy
Tremendous increases of energy and water will be required in the near future as
the world's population increases from 6 to over 9 billion. Even now, some
2 billion people do not have access to a reliable supply of electricity. Somehow
capacity must be increased to meet this demand, and at the same time
production and use of energy must be made more efficient. To be sustainable,
however, these objectives should be achieved without energy production having
any negative impact on either human health or the environment. As for industry,
the tools available include technological fixes, development of alternative or
renewable energy sources, and a judicious mix of management options that
include economic incentives and legislation. Priorities in developed and
developing countries may be very different.
Managing Risks
Water related hazards, such as floods, droughts, tropical storms, erosion and
various kinds of pollution should be factored into any integrated approach to
water resource management and policy. Although it is the world's poor who
suffer the most when exposed to such dangers, everyone's security is at stake.
One way to minimize risk is to develop more capacity in the monitoring and
forecasting of extreme events. With this information, appropriate early warning
systems and infrastructure can be installed, and new planning strategies
devised. It is also necessary to ensure that climate variability and change have
their place in the total picture.
Sharing Water Resources
Competition over scarce or poorly allocated resources can lead to tension and
insecurity. Therefore decision-makers, communities, governments and regions
must strive to develop policies that allow for sharing among all stakeholders.
Many different interests are at stake and equitable solutions must be found:
between cities and rural areas, rich and poor, arid lands and wet lands, public
and private, infrastructure and natural environments; mainstream and marginal
groups, local stakeholders and centralized authorities. At the regional and
international level, many river basin and aquifer authorities are developing
integrated approaches that stress cooperation of the shared resource. A UNESCO
programme called
(From Potential Conflict to Cooperation Potential) is
Valuing Water
This whole question is among the most controversial of all the challenges
identified in the Ministerial Declaration emerging from the Second World Water
Forum in the Hague. In many societies the whole notion of putting a price tag on
someting as intrinsically valuable as water is unacceptable. Yet services must be
paid for. There is also much disagreement about how to balance the costs of
provision and wastewater treatment with the goal of equity and finding ways to
meet the needs of poor and vulnerable populations. Creative new partnerships
between the public and private sectors should be developed, along with
accounting and taxation systems that take full account of environmental and
social factors.
Ensuring the Knowledge Base
This target takes account of the whole range of technical and non-technical
information and knowledge, and seeks ways for all societies to benefit from their
development, exchange and dissemination. National authorities and resource
managers need sound scientific data on which to base their projections and
decision-making. Stakeholders need access to other kinds of information and
educational opportunities if they are to understand and participate in the process
as responsible citizens. With the development of modern telecommunications
and the global marketplace, it is more than ever necessary to ensure that every
community and country play a role in building a more sustainable future.
Governing Water Wisely
This challenge area is particularly complex and sensitive. It moves the debate
about sustainability beyond water management issues and into processes of
political, social and institutional change. Many countries agree that good
governance means allowing every sector of society to participate in the decisionmaking process and that the interests of all stakeholders should be taken into
account. However, mechanisms for doing so are not always in place, even if
decentralization and the increasing involvement of civil society are worldwide
trends. International cooperation and assistance may play a crucial role particularly in developing countries - by helping to strengthen institutional
capacity.
GLOBAL SCENARIOS ON WATER - PROPOSAL
These specific water variables will be computed as part of quantitative scenarios (if feasible) and
include:
 Changing average (annual) water availability as affected by changes in climate, land use, and
water abstractions
 Changing frequency of hydrological extreme events (floods and droughts)
 Changing average water use
 Changing river connectivity (dams and reservoirs)
 Changing river morphology
 Changing ecological (biological and chemical) conditions of aquatic ecosystems including
aquatic & riparian biodiversity
 Changing land use
 Changing forms and impacts of water governance
They should have two time frames:
 �� short (up to 2015 or 2020) in order to address the
 issue of the Millennium Development Goals and
 other policies relevant to the next decade
 �� long (up to 2100) to take into account the impacts
 of long term changes in climate, land use and
 socio-economic driving forces.5
9. What is the Audience for New Global Scenarios?
New global water scenarios should be targeted to a wide audience, including:
Decision-makers at different levels. Decisions regarding water availability and water use are being
made everyday at the local, national, and international scales.
Stakeholders. Many people around the world are affected (positively or negatively) by changes in
water accessibility and use, and many different social and economic actors (governmental,
nongovernmental,
and private) are involved in water issues. Scenario exercises can provide a neutral arena for
identifying and discussing water issues from different viewpoints and interests.
The scientific community concerned with changes in the earth system. The future condition of the
global water system will be affected by climate and other global changes. In turn, changes in the
global water system
will have a profound impact on other parts of the earth system such as global patterns of climate,
vegetation and land use. Scenarios can provide a vehicle for better anticipating future changes in the
global water system.
International organizations concerned with water. Since the lifetime of some water infrastructure is
several decades, decisions today must factor in expected long-term changes in the global water
system. Scenarios can provide information about the magnitude and nature of these changes and
global ‘hot spots’ of change.
General public and students at the university- and other levels. Global water scenarios provide an
excellent
device for envisioning the future and understanding the many complicated factors that will influence
future changes in the global water system. They can be used very effectively to communicate
complex ideas about future water resources to a broad general and academic audience.
Scenarios for Urban Water Management: Europe and Developing Countries
Dragan Savic
Director
Centre for Water Systems
University of Exeter
UK
[email protected]
Abstract
Urbanisation and its associated environmental impacts are occurring at an unprecedented
rate. While in 1900 just fourteen percent of the world's population lived in cities, that number
was estimated to reach over fifty per cent by the year 2000. About 80% of European
population lives in urban areas. Urbanisation brings increased demand for energy, raw
materials and results in pollution and production of waste. It also brings an enormous
pressure on water as natural resource, thus stressing the necessity of integrated
management of Urban Water Systems. Governments around Europe are urged to take
action on the formulation and implementation of policies for the integrated management of
water resources in large cities and towns, to control pollution from sewage and effluents; and
to protect groundwater from over-utilisation and pollution. In less fortunate parts of the world,
notably the developing countries over 1 billion people, or 18% of the world's population, lack
access to safe drinking water and over 2.4 billion people do not have adequate sanitation.
The European Commission is promoting the development of an EU water initiative whose
overall target should be the millennium target to halve the proportion of people lacking
access to safe drinking water by 2015, together with a complementary target on sanitation.
This talk will: (i) emphasise the importance of IUWM, (ii) the complexity of integrated urban
water management (IUWM) issues in both European and developing countries, (iii) contrast
the key issues in develop and developing countries, and (iv) point to a way forward where
urban scenario elements could be combined to manage uncertainties associated with IUWM
by providing design and management strategies for urban water systems that will perform
reasonably well in the face of significant uncertainty.
Scenarios for agricultural water demand –
experience from WADI and other projects
Keith Weatherhead
Institute of Water and Environment, Cranfield University at Silsoe, UK.
Water abstraction for agriculture, predominantly for irrigation, is one of the major water uses
in Europe. In many areas it is by far the largest use; furthermore it is concentrated in the
driest catchments, peaks in the driest months when resources are scarcest, and is mostly
consumptive – unlike domestic and industrial abstractions, there are often no return flows.
Its impact on the environment and other abstractors is therefore even greater than the raw
data suggests.
Clearly any water supply/demand scenarios must include agricultural demand.
At its simplest, on one site, agricultural water demand can be modelled as the product of
cropped areas (ha), proportions irrigated (%), irrigation needs (mm per annum) and
application efficiencies (%). For regional studies, we also need to consider spatial variation
in
soils, climate, cropping pattern and irrigation method (eg Weatherhead and Knox, 2000).
Looking forward, changes in socio-economic scenarios and government policies will affect
which crops are grown and which are irrigated, and the attitudes of farmers to water
conservation. Climate change will affect which crops are grown and which are irrigated, but
also where those crops are grown and how much those crops need.
Whilst the above is not simplistic to model, and will often require expert judgement alongside
hard science, the methodology is feasible, and has been applied in various projects,
including for example the agricultural part of Climate Change and Demand for Water
(CCDeW), forecasting future water demand in England and Wales (Downing et al, 2003).
However, these studies have raised a number of issues that need to be highlighted in
defining the Framework 6 project component on agricultural water demand, that do not
necessarily all apply to domestic or industrial demand scenarios.
Calculating “unconstrained demand” (free abstraction with no restrictions) is meaningless
in highly stressed catchments; it cannot and will not be supplied. But which “demand” are
we interested in?
Market feedback loops are important. Changes in crop production or yield in one area
impact on cropping, and hence water demand, in other areas.
Increased atmospheric CO2 will change cropping and water demand irrespective of
climate (weather) change.
Adaptation is important. Farmers will respond to some water constraints, depending on
the cost of the water. But the extent of adaptation may depend as much on government
policies as the farmers. Again, which “demand” are we interested in?