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Scenario formulation
Scenario-based planning is a structured way of thinking about what might happen in the future
Scenarios are descriptions of possible futures– NOT predictions – to help us to test and compare likely
outcomes of different decisions or trends For BDP, scenarios describe possible changes
related to water resources over the next 5 to 20 years
DemandsConsumptiveAgriculture
Culture fisheries
Water supplyEnvironmental
In-streamFish
Salinity controlEnergy
Navigation
Climate
Sea level rise
Increased dry season
demands
Higher drought risk
Increased flood flows and
frequencies
Infrastructure
Dams
Irrigation and drainage
Flood control
Salinity control
Dredging and river works
Water supply and sanitation
Management practices
Catchment management
Energy production
Irrigation husbandry
Fisheries management
Pollution control
Changes affecting water resourcesScenario components
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Scenario Components
Current water resources conditions (baseline) Key water related sectors Trends and risks affecting water resources
– predictable (population, irrigation growth)– uncertain (climate change)
Possible interventions and developments
Demands Climate Infrastructure Management practices
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Sub-areas and scenarios
BDP is building regional scenarios based on sub-area studies– to ensure local issues
and concerns are included
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Sub-areas and scenarios
Sub-area studies provide scenario components for each sub-area:– trends and risks– proposed projects and programs– key issues and sectors
Sub-area scenarios components form the building blocks for regional scenarios
Identify common issues, trends, sectors from all sub-areas AND basin-wide or trans-boundary issues
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Sub-area to region
BUT Not all issues that are important at sub-area
level have regional significance– eg salinity in NE Thailand is very important at local
scales – but impacts do not (yet) reach the Mekong Scenarios for sub-areas may not be relevant
to the whole region Sub-area analysis and scenario components
are ESSENTIAL – sub-area scenarios are optional
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Regional scenarios
Regional scenarios put together – regionally significant trends, issues, risks
from each sub-area– proposed projects and programs from
each sub-area (cumulative effects)– regional projects and programs
Build regional scenarios from sub-area scenario components– not by combining sub-area scenarios
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BDP Scenarios
BDP will need to consider MANY scenarios Large number of exploratory runs to establish
major hydrological patterns / constraints– Analysis mainly of hydrological parameters– Sensitivity analysis
Smaller number of “full” runs– Include social and economic analysis– Much of social and economic analysis may take
place outside the DSF
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Scenario Formulation - the key stepsAgreed at Regional Forum in August 2003
1. Collect regional and sub-area data2. Analyse for water-related issues, trends, risks3. Identify potential water-related developments4. Estimate size range for each trend, development, risk5. Estimate regional significance of water-related impacts
for each trend, development, risk6. Assemble scenarios (groups of possibilities) from the
above components7. Test outcomes of scenarios against assessment
criteria using DSF or other means8. Repeat 6 and 7 until feasible and acceptable scenarios
are found
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Convert scenario to model formats where possible…….
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Scenario definition and reporting in the DSFE.1 Scenario
ObjectiveFor each planning issue, planners define a scenario objective that states what is to be tested against which potential sectoral interests
E.2 Scenario Components
Agreement is reached between the DSF modelling team and planners on the scenario’s components, i.e. hydrological conditions, prevailing demands and interventions in place
E.3 Relevant trans-boundary issues by Sector
The DSF modelling team agrees with the planners which relevant issues are to be investigated when running the scenario
E.4 Indicators relevant to trans-boundary issues
The DSF modelling team agrees with the planners which indicators are to be tested for each selected trans-boundary issue
E.5 Tools for testing changes in indicators
The DSF modelling team selects the tools required to test the selected indicators
E.6 Reporting The DSF modelling team agrees with the planners how information on each indicator is to be reported
Scenario definition and reporting in the DSFE.1 Scenario
ObjectiveFor each planning issue, planners define a scenario objective that states what is to be tested against which potential sectoral interests
E.2 Scenario Components
Agreement is reached between the DSF modelling team and planners on the scenario’s components, i.e. hydrological conditions, prevailing demands and interventions in place
E.3 Relevant trans-boundary issues by Sector
The DSF modelling team agrees with the planners which relevant issues are to be investigated when running the scenario
E.4 Indicators relevant to trans-boundary issues
The DSF modelling team agrees with the planners which indicators are to be tested for each selected trans-boundary issue
E.5 Tools for testing changes in indicators
The DSF modelling team selects the tools required to test the selected indicators
E.6 Reporting The DSF modelling team agrees with the planners how information on each indicator is to be reported
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Convert scenario to model formats where possible…….
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….or just think it through
with expert help
eg water quality
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Assessing Scenarios
Outcomes of different scenarios are assessed and compared against regional planning goals using assessment criteria and indicators / targets– does the scenario meet development goals?– does it obey WUP Rules?– are key Basin assets protected (fisheries,
water quality)?– how does it compare with other scenarios?
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Comparing and ranking options
Comparison of options is complex Objectives may not be fully compatible
– eg maximum economic return vs conservation of resources
Outcomes may not be comparable– eg environmental damage vs social good
Trade-offs may be required– Negotiation and consultation
Multi-criteria assessment
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Using scenarios
Identify preferred development options– define strategies for Basin development– identify the types of projects and programs
required Determine acceptable trade-offs between
development and resource protection– define the amount of potential development
available before unacceptable degradation of the river occurs
– set minimum flow rules
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