Using the DSF to assess scenarios

Some things it will do for you

- and some things it won’t

Example Scenario: Stung Treng Hydropower Dam

• Scenario: hydropower dam at Stung Treng– assume that the size and operating rules of the dam are given

• What can the DSF tell us about the outcomes in terms of – hydrology– environment– social impacts– economic impacts

Option 1

Hydrology

• DSF tells us LOTS about hydrology– changes in flow patterns at different places

due to dam– flow impacts for different operating rules– changes in flood extent and frequency

Time Series Analysis Tool

01/ Jan/ 1990 - 31/ Dec/ 2000

Stung Treng: f lowgfedcb M.A.: Stung Treng: f lowgfedc

8/26/20002/26/20008/28/19992/27/19998/29/19982/28/19988/30/19973/1/19978/31/19963/2/1996

flow

(cum

ecs)

55,000

50,000

45,000

40,000

35,000

30,000

25,000

20,000

15,000

10,000

5,000

Hydrology - existing flow conditions at Stung Treng

Time Series Analysis Tool

01/ Jan/ 1990 - 31/ Dec/ 2000

Stung Treng: f lowgfedcb M.A.: Stung Treng: f lowgfedcb

8/26/20002/26/20008/28/19992/27/19998/29/19982/28/19988/30/19973/1/19978/31/19963/2/1996

flow

(cum

ecs)

55,000

50,000

45,000

40,000

35,000

30,000

25,000

20,000

15,000

10,000

5,000

New flow conditions after dam construction - Stung TrengFake Data

Time Series Analysis Tool

01/ Jan/ 1995 - 31/ Dec/ 2000

Kratie: f lowgfedcb M.A.: Kratie: f lowgfedcb

12/5/200012/6/199912/6/199812/6/199712/6/199612/7/1995

flow

(cum

ecs)

55,000

50,000

45,000

40,000

35,000

30,000

25,000

20,000

15,000

10,000

5,000

New flow conditions after dam construction - Kratie

Fake Data

Current major flood extent

Major flood extent with dam

Fake Data

FloodingDSF gives changes in extent and duration of flooding, and information about the type of land flooded (land use, wetland type)

NO information on

• impact on ecosystems

• impact on fish production

• value of reduced damage from floods

….etc

Consult an expert!

Flooded area (ha)

Tre

y rie

l ca t

ch

Before dam

After dam

Environment - wetlands

GIS in DSF gives location of wetlands, and some information on type

Time Series Analysis Tool

01/ Jan/ 1995 - 31/ Dec/ 2000

Kratie: f lowgfedcb M.A.: Kratie: f lowgfedcb

12/5/200012/6/199912/6/199812/6/199712/6/199612/7/1995

flow

(cum

ecs)

55,000

50,000

45,000

40,000

35,000

30,000

25,000

20,000

15,000

10,000

5,000

NO information on

• response of wetland plants or animals to changes in flow

• how changes would affect subsistence use

• value of wetland produce and how this would change

Consult an expert! (or wait for EP flow management program)

Social Impacts

GIS in DSF gives • location of villages• population• some information on social

conditions (from Census, provincial level)

NO information on• subsistence livelihoods• resettlement options and

preferences• cultural values• ethnic minorities…..etc

Consult an expert!

Economic impactsGIS in DSF gives some information on land use, irrigation

NO information on

• value of ag production

• non-agricultural industries

• value of power generated

• costs of relocation

Consult an expert!

Using the DSF

BDP will need to consider MANY scenarios• Large number of exploratory runs to establish

major hydrological patterns / constraints– Analysis mainly of hydrological outcomes

• Smaller number of “full” runs– Include social and economic analysis– much of social and economic analysis will take place

outside the DSF

Time Series Analysis Tool

01/ Jan/ 1990 - 31/ Dec/ 2000

Stung Treng: f lowgfedcb M.A.: Stung Treng: f lowgfedcb

12/5/200012/6/199912/6/199812/6/199712/6/199612/7/199512/7/199412/7/199312/7/199212/8/199112/8/1990

flow

(cum

ecs)

55,000

50,000

45,000

40,000

35,000

30,000

25,000

20,000

15,000

10,000

5,000

Scenarios

• Scenarios are descriptions of possible futures– help us to test and compare possible

outcomes of different decisions

• For BDP, scenarios describe possible changes to the water resources system over the next 5 to 20 years

DEVELOPMENT SCENARIOS

PLANNING SCENARIOS

BASELINE SCENARIO

Scenarios

• Available water resources– supply, demand / use, condition

Trends affecting water resources– predictable (population growth)– uncertain (economic conditions,

climate change)

Possible interventions and developments

– structures, management practices

Impact analysis• Impacts of different scenarios are described using

expert opinion and models (DSF)– hydrological– environmental– social– economic

• Impacts may be poorly understood / little data available / difficult to quantify– particularly for social and economic impacts– work with existing knowledge– qualitative / descriptive vs quantitative

DSF

DSF and other sources

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?

Strategies and short lists

• Preferred scenarios are used to define development strategies– identify priority projects consistent with strategies

• Trade-offs may be required between different goals – eg economic development and environmental

protection– scenario analysis helps define what is gained and

what is lost

• Final decisions made by national governments

Formulating scenarios• Use scenarios to test bounds of system, answer

questions like– What will be the impact of dams in Yunnan on ecosystems

of the LMB? Will they have a significant impact on Tonle Sap fisheries? availability of water for irrigation? flood frequency?

– If population keeps growing at the current rate, will there be sufficient water to meet irrigation demands in 20 years?

• Use scenarios to examine impacts of specific development options– possible to analyse individual interventions, but DSF is

built for regional scale assessments (not local)

Some example scenarios

11 Nominal baselineNominal baseline22 Climate changeClimate change33 Catchment cover changeCatchment cover change44 High irrigation growthHigh irrigation growth55 Impact of China damsImpact of China dams66 Impact of LMB damsImpact of LMB dams77 Impact of flood embankmentsImpact of flood embankments

……………………6767 Expansion of irrigation in eastern CambodiaExpansion of irrigation in eastern Cambodia68 68 Kok-Ing-Nam diversionKok-Ing-Nam diversion6969 Impact on saline intrusion of changing farming Impact on saline intrusion of changing farming

systems in Deltasystems in Delta7070 Hydropower development in Central LaosHydropower development in Central Laos