Download - Using the DSF to assess scenarios
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