1. 1 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

2. Demands Consumptive Agriculture Culture fisheries Water supply Environmental In-stream Fish Salinity control Energy Navigation Climate Sea level rise Increased dry season demands Higher drought risk Increased flood flows and frequencies I nfrastructure 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

3. 3 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 I nfrastructure Management practices

4. 4 Sub-areas and scenarios BDP is building regional scenarios based on sub-area studies –to ensure local issues and concerns are included

5. 5 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

6. 6 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

7. 7 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

8. 8 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

9. 9 Scenario Formulation - the key steps Agreed at Regional Forum in August 2003 1. Collect regional and sub-area data 2. Analyse for water-related issues, trends, risks 3. Identify potential water-related developments 4. Estimate size range for each trend, development, risk 5. Estimate regional significance of water-related impacts for each trend, development, risk 6. Assemble scenarios (groups of possibilities) from the above components 7. Test outcomes of scenarios against assessment criteria using DSF or other means 8. Repeat 6 and 7 until feasible and acceptable scenarios are found

10. 10 Convert scenario to model formats where possible…….

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12. Scenario definition and reporting in the DSF E.1Scenario Objective For each planning issue, planners define a scenario objective that states what is to be tested against which potential sectoral interests E.2Scenario 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.3Relevant 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.4Indicators 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.5Tools for testing changes in indicators The DSF modelling team selects the tools required to test the selected indicators E.6Reporting The DSF modelling team agrees with the planners how information on each indicator is to be reported

13. Scenario definition and reporting in the DSF E.1Scenario Objective For each planning issue, planners define a scenario objective that states what is to be tested against which potential sectoral interests E.2Scenario 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.3Relevant 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.4Indicators 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.5Tools for testing changes in indicators The DSF modelling team selects the tools required to test the selected indicators E.6Reporting The DSF modelling team agrees with the planners how information on each indicator is to be reported

14. 14 Convert scenario to model formats where possible…….

15. 15 ….or just think it through with expert help eg water quality

16. 16 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?

17. 17 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

18. 18 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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