Transcript 30 Years of Global Water Projections

REVIEW OF THE METHODS FORWATER RESOURCES
PROSPECTIVE:
WHAT CAN WE LEARN FOR THE WATER FRAMEWORK
DIRECTIVE?
Ruud Van der Helm (ENGREF, France)
[email protected]
and
Adeline Kroll (IPTS, JRC-EC, Spain)
[email protected]
Lille III Conference
18-19/03/02
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
1
Water Projections at the Global Level
•20th century, water planning focused on projections using variables
such as e.g., populations, per-capita water demand, agricultural
production, levels of economic productivity etc.
•However, these projections on water demand typically ignored any
analysis of human needs, water required for ecosystems or actual
regional water availability
•Next step to this approach (still) is to identify projects able to
bridge the gap between projected water demand and estimated
available water supply
•Basic assumption is in this approach that building more physical
infrastructures could meet projected shortfalls
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
2
Today’s debate...
…lies between those who believe that the problem is
primarily technical (e.g., more efficient technology) and those
who believe that reorganisation and co-ordination of water
policy process will rationalise decisions toward a waterdemand planning.
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
3
30 Years of Global Water Projections
•Early models (e.g., Nikitopoulos 1962) broke down water
withdrawals per sector (agriculture, domestic, industrial) and by
regions. Basic assumption was to estimate water needs using
average annual per capita water withdrawals per sector based on
population estimates;
•Alternative models (“business-as-usual” with alternative model)
introduced by L’vovich (1974) who first considered water-reuse;
•In view of Mar de Plata (Argentina, UN Water Conf, 1977), De
Mare (1976) used works by Russians Kalinin and Shiklomanov
(1974) who first considered reservoir losses by evaporation;
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
4
30 Years of Global Water Projections
•Sustainability criteria and limits introduced by Gleick (1997);
•Policy drivers introduced by Raskin et al. (1997) with their
“Reference” BAU and “Policy” models (socioeconomic conditions
considered)
•“WaterGap:” model (Alcamo et al. 1997) evaluated water use for
nearly the entire land surface of the world;
•Recently, models have increasingly gained in complexity (sub and
sub-sub models…)
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
5
Global Water Projections: What’s Next?
•Early global water projections turned out to be
wrong: greatly overestimated water demand by about
50% of what was expected 30 years ago;
•Depended on straightforward extrapolations of
existing trends;
•Ignored environmental, ecological and social
variables now considered the most recent global water
projections.
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
6
4 Cases
• World Water Vision (World Water Council)
•Participatory Vision Development based on reference scenarios
•Globesight (Global Foresight) (CWRU Ohio USA)
•Systems Dynamics with ‘Human in the loop’
•WaterGAP (Water Global Assessment and Prognosis) (CESR
University of Kassel)
•Simulation of Resources Dynamics
•WEAP (Water Evaluation and Planning System) (SEI Boston)
•Policy Analysis Decision Support System
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
7
Scenarios
Model World Water Vision
Globesight
WaterGAP
WEAP
Baseline
vs. Base-line scenarios
policy scenario*
Policy scenarios
Baseline scenarios; Policy scenarios
policy scenarios
Quantitative vs. Qualitative
qualitative*
(quantification added)
Quantitative
Quantitative
Semi-quantitative
Exploratory vs. Exploratory
anticipatory*
Exploratory
Exploratory
Exploratory
Main approach
Human-in-the-loop
3 water intensity Policy alternatives
scenarios
Type of scenario
Narrative (storylines)
2 climate scenarios
Place in
process
ECOLE NATIONALE
the Scenario development Scenario
Scenario
at the start and during development during development
the process; part of the the process
upstream of
core debate.
process
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
8
Scenario
development
the upstream of
process
the
Socio-economic driving forces
Socio-economic
driving forces
ECOLE NATIONALE
WaterGAP
WEAP
Demography
Demography
Population
Policies
Technology
Energy
Income
Costs
Society
Economy (GDP)
Electricity
Demand factors
Governance
Agriculture
Water Intensity
Pollution
Economy
Agricultural intensity
Supply
Environment
Water use efficiency
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
9
World Water Vision Globesight
Participation
Participation
ECOLE NATIONALE
Globesight
Large scale
consultations among
stakeholders through
contributions and
feedback to
intermediate versions
of documents and
through workshops.
Decentralisation of the
exercise in order to
foster appropriation
and legitimation.
Cybernetical view
of participation.
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
10
World Water Vision
WaterGAP
Scientists-based
model which does
not include
Human beings are
participation.
seen as submodel.
However,
The goal-seeking
WaterGAP can
behaviour of
handle participation
algorithms is
upstream (in
replaced by the
defining sociogoal-seeking
economic
behaviour of human
scenarios) and
'models'.
downstream,
through discussion
of the results.
WEAP
Decision support
system in which the
(individual) user
can assess
different scenario
possibilities.
No citizen
participation is
included in the
concept.
Lessons for the FDW
•There are more valid answers to foresights
•Data remains a problem.
•Interaction between scenarios and modelling
•Refinement of driving forces
•Foresights become valuable during their evolution
•The demand for participation can be answered in different
ways ( towards participatory scenario development?)
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
11
Recommendations
• Strive towards continuous foresights per river basin
• Combine scenario Development with arithmetic (modelling)
• Strive for participation in scenario development
• Explore to a larger extent existing experiences
ECOLE NATIONALE
DU GENIE RURAL DES EAUX ET DES FORÊTS
ENGREF
12