Decadal Climate Variability and the Operation of Water Resource Systems

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Decadal Climate Variability and the Operation of
Water Resource Systems

• Francisco de Assis de Souza Filho
• Upmanu Lall, Hyun-Han Kwon

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Outlines

• Impact of Decadal Climate Variability in
  Reservoir in Brazil
• Northeast of Brazil
• Hydropower in Brazil
• Impact of Decadal Climate Variability in
  Reservoir in Colorado River in US
• Notes to adaptative hydrosystem operation

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Brazil
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Quixeramobim
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Historical Notes -Ceará State

• Drought 1777
• Death of 7/8 cows
• Start the end of Charqueadas
• Drought 1877
• Exodus The Fortaleza City increase from 25,000
  to 100,000 in three months
• more than 1000 deaths in Fortaleza (Capital of
  Ceara) in one day (12/12/1878)
• Death 500.000 inhab. In the dry lands of
  Norteaste of Brazil
• Drought becomes a PUBLIC problem

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Fortaleza Rain 1849-2006
1877 Drought
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Fortaleza - Precipitation
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Orós Reservoir Inflow
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Orós Reservoir Yield with 90 of Reliability
calculate to 30 years windows(Using Orós Inflow
Historical Time Series)
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Orós Reservoir Yield with 90 of Reliability
calculate to 10 years windows(Using Orós Inflow
Historical Time Series)
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Parana River Basin Hydropower Production

• Streamflow increase after 70s
• This basin has 60 of Brazil Hydropower
  Production
• 90 of Brazils electricity is produced by
  hydropower

River Flow m3/s
Tucci
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Hydropower Production in Brazil
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Hydroletric Sector BrazilPCA
93 of Electrical Energy Production in Brazil
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Hydroeletric PC1
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Hydro PC1
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Colorado River
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U.S. Geological Survey
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Demand In Colorado Basin
Systems Losses
Upper Basin Demand (4.5-5.0 maf)
Evaporation
Evaporation and Others 1.2 maf
Lake Powel
Mexico Demand (1.5 maf)
Yield
Inflow
Upstream Intake Actual 4.0 maf (Consumptive
use) 0.6 maf (Evaporation) 2060
5.4 maf (Consumptive use) 0.6 maf
(Evaporation)
Lower Basin Demand (7.5 maf)
Inflow Downstream (Gain) 0.7 maf
Total Demand 7.54.51.5 13.5 maf/year
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Some Relevant Questions

• How should water allocation and reservoir
  operation rules be changed if we expect a
  systematic change in the long term mean, variance
  and other statistics of stream flow, but are
  faced with considerable uncertainty as to the
  nature and magnitude of this change?
• What are the implications of constructing
  additional reservoir storage or the removal of a
  dam given that the next 20 or 30 years may see a
  significant change in flow attributes?
• How does one interpret climate variability in the
  past several centuries in the context of what can
  be allocated and when, and to assess the
  frequency, severity and duration of supply or
  allocation failures?
• What aspects of these multi-decadal system
  performance attributes are modified by reservoir
  storage of a particular size, and which risks
  remain residual to storage provision?

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Simulation using Historical Inflow
Data(1906-1995)
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From Connie Woodhouse
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INFLOW
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Colorado River

• The Compact allocation was based on an
  anomalously wet period, which was followed by
  multiple decades with well below average flow. 
• Multi-century Colorado River streamflow
  reconstructions show preferred regimes with
  recurrence structure or cycles, whose role needs
  to be understood in the context of managing
  climate risk for the long run performance and
  adaptive application of the existing Colorado
  River Compact, or for the modification of the
  Colorado River Storage Projects components or
  operating rules.
• Here, we use more than 5 centuries of
  reconstructed streamflow to assess some aspects
  of the dynamic climate risk faced by this system,
  with a specific focus on the example questions
  listed above.

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Colorado River

• We derive the performance attributes of the
  system through simulations of the Glen Canyon
  reservoirs mass balance, and explore the
  time-frequency structure of reservoir storage and
  supply/deficit in supply from the reservoir. We
  note that the Glen Canyon reservoir is effective
  in ameliorating the impacts of inter-annual and
  decadal climate variability, but multi-decadal
  climate risk, as often discussed in the context
  of the history of the Colorado River Compact is
  not significantly reduced.
• The prospects for developing a strategy to
  identify the operative climate regime, and the
  potential scenarios for the short, medium and
  long run inflows, and the use of these scenarios
  to develop an adaptive management strategy for
  the system are necessary.

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Final Remarks

• Low frequency (decadal and longer) climate
  variability pose a significant challenge to the
  management and planning of water resources
  infrastructure.
• Both climate aspects lead to some common
  institutional challenges for design, operation
  and policy formulation or implementation. 
• The adaptative strategy to low frequency climate
  variability must incorporate institutional
  infra-structure and physical infrastructure

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Final Remarks

• Institutional infrastructure to adaptation
• Realocate water
• Financial mechanism to mitigate impact of
  variability (insurance)
• Physical infrastructure
• Using the spatial variability to mitigate the
  local risk (trans-basin)
• New supply sources