1 / 30

Task 1 – Projection Selection Considerations

Task 1 – Projection Selection Considerations Task 3.1 – Adjusting Inflow Data for Reservoir Simulation Models. Levi Brekke (Reclamation, Denver, CO). 9 June 2009, Portland, OR. Task 1 – Projection Selection Considerations. Our Focus: Hydrology-related Impacts. Task 1.

kura
Télécharger la présentation

Task 1 – Projection Selection Considerations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Task 1 – Projection Selection Considerations Task 3.1 – Adjusting Inflow Data for Reservoir Simulation Models Levi Brekke (Reclamation, Denver, CO) 9 June 2009, Portland, OR

  2. Task 1 – Projection Selection Considerations

  3. Our Focus: Hydrology-related Impacts Task 1 1) Survey Global Climate Projections over the study region 3) Define water suppliesandhydrology-related inputs in terms of climate info from 2.b; characterize uncertainties Hydrologic Response 2.a) Decide how/whether to cull the information. 4) Assess operations and dependent resource responses; characterize uncertainties 2.b) Decide how retained information will be used.

  4. Information from CIG • Hybrid • Paired sequences of climate and hydrology data • Sequence #1: Observed Historical • Sequence #2: “Climate Changed” • Specific to a given projection and a given future period

  5. Information from CIG • Hybrid • Observed Historical Climate and Hydrology • Climate • Defined by 1916-2006 (91 years) daily observed weather • Hydrology • VIC-simulation forced by daily observed weather • Produces 91 years of daily gridded water balance • Post-simulation routing produces 91-years of routed natural runoff to locations of interest (e.g., inflow locations to reservoir simulation models) • Further post-analysis converts natural runoff to modified flows • Reflects observed statistics and sequence

  6. Information from CIG • Hybrid • Climate Changed Hydrology • Climate • 91 years of daily weather reflecting statistics of a given projection and future period in that projection (Alan’s talk) • 2010-2039 (~2025) • 2030-2059 (~2040) • Hydrology • Similar to Observed Historical (91 years, daily), but reflects different climate • Repeated for 20 climate projections x 2 future periods  40 candidate Hybrid scenarios from CIG

  7. Information from CIG • Hybrid scenario selections • How many of CIG’s Hybrid scenarios do we want to use in this study? • Guiding philosophy: • Reflect the “spread” of climate change information from CIG • Reflect the central tendency of this information also (e.g., centrally estimated “climate change” increment) • Potential scheme … • Reclamation 2009, San Joaquin River Restoration Program (SJRRP) PEIS/R

  8. Projection Selection Factors:SJRRP Choices • Climate Periods: 1971-2000, 2011-2040 (accomplishments horizon is through 2030) • Climate Change Metrics: Period Mean-Annual Tair & P (CVP performance trends with annual P) • Climate Change Location: “Above Millerton” (more interest on water supply local to SJRRP) • Change Thresholds of Interest: 10 to 90 %-tile changes like OCAP, plus choice near medians

  9. Implementation of SJRRP Factors:Step 1) Survey projections “Above Millerton” 1a. From website, download monthly Tair & P time series. 1b. Compute historical and future period “climate metrics” for every projection. 1c. Compute historical-to-future period changes in “climate metric” for every projection.

  10. Implementation of SJRRP Factors:Step 2) Construct scatterplot of projections’ mean-annual changes in temperature and precipitation

  11. Implementation of SJRRP Factors:Step 3) Select 4 bracketing projections, plus one central from the scatterplot produced in Step 2) • (drier, more warm) ncar_ccsm3_0, run 6, B1 • P change: -13.6% T change: +2.8F • (drier, less warm) mri_cgcm2_3_2a, run 4, A1b • P change: -9.8% T change: +0.9F • (wetter, less warm) mri_cgcm2_3_2a, run 1, B1 • P change: +16.3% T change: +0.9F • (wetter, more warm) inmcm3_0, run 1, A2 • P change: +9.0% T change: +2.6F • (“central”) mpi_echam5, run 1, A1b • P change: -0.3% T change: +1.8F

  12. Implementation of SJRRP Factors:Step 3) Select 4 bracketing projections, plus one central from the scatterplot produced in Step 2)

  13. Implementation of SJRRP Factors:Step 4) Check how 4 bracketing projections at “Above Millerton” encapsulate spread at other locations • Above Millerton: Southern Central Valley • Above Folsom: Mid-Central Valley • Above Shasta: Northern Central Valley

  14. Above Millerton (southern valley) Implementation of SJRRP Factors:Step 4) Check how 4 bracketing projections at “Above Millerton” encapsulate spread at other locations

  15. Implementation of SJRRP Factors:Step 4) Check how 4 bracketing projections at “Above Millerton” encapsulate spread at other locations Above Folsom (mid-valley)

  16. Implementation of SJRRP Factors:Step 4) Check how 4 bracketing projections at “Above Millerton” encapsulate spread at other locations Above Shasta (northern valley) Main Point: Projection spread varies by location. So would selections for bracketing and “central” projections. We anticipate this would be the case in our study also…

  17. Information from CIG • Hybrid • Preliminary Selection Plans • One “Base” Sequence: Observed Historical • Ten “Climate Changed” Sequences • Five for ~2025 climates (4 bracketing, 1 central) • Five for ~2040 climates (4 bracketing, 1 central)

  18. Information from CIG • Transient • single sequences of climate and hydrology data • Sequence spans “Simulated Historical” to “Projected Future” • “Simulated Historical” • Bias-corrected during 1950-1999 to be statistically consistent with observed-historical • Does not have the same sequencing characteristics

  19. Information from CIG • Transient • Climate Changed Hydrology • Climate • 1950-2099 (150 years) of daily weather • reflects evolving monthly statistics of a given projection • reflects relatively daily variability from observed historical but • with potentially more extreme scaling/shifting on a month-specific basis compared to Hybrid (Alan’s talk) • With more discontinuities (all month boundaries) compared to Hybrid • Hydrology • 1950-2099, daily • Repeated for 20 climate projections  20 candidate Transient projections from CIG

  20. Information from CIG • Transient • Preliminary Selection Plans • All transient projections that underly selected Hybrid scenarios • Five for ~2025 climates (4 bracketing, 1 central)  five transient projections • Five for ~2040 climates (4 bracketing, 1 central)  five transient projections • Check for overlap among the five for each period • Total selection will range from 5 to 10.

  21. Task 3.1 – Adjusting (or Preparing) Inflows for Reservoir Simulation

  22. Our Focus: Hydrology-related Impacts Task 3.1 1) Survey Global Climate Projections over the study region 3) Define water suppliesandhydrology-related inputs in terms of climate info from 2.b; characterize uncertainties Hydrologic Response 2.a) Decide how/whether to cull the information. 4) Assess operations and dependent resource responses; characterize uncertainties 2.b) Decide how retained information will be used.

  23. Information from CIG  Task 3 • Hybrid • Preparing Inflow Data for Reservoir Simulation • Model time-steps and traditional periods vary: • BPA HydSim: 14-period, WY 1929-1999 • USACE AutoReg/SSARR: daily, WY 1929-1999 • USACE HEC/ResSim: daily, WY 1929-1999 • USACE HYSSR: 14-period, WY 1929-1999 • Reclamation ModSim-Deschutes: monthly, wy1929-1999 • Reclamation ModSim-Snake: monthly, wy1928-2001 • Reclamation ModSim-Yakima: monthly, wy1929-1999

  24. Information from CIG  Task 3 • Hybrid • Preparing Inflow Data for Reservoir Simulation • Scenario Inflows need to: • reflect decision on simulation period (max: 91 years) • reflect each model’s inflow definitions • Considerations for Climate Change Hydrology: • reflect same level of basin depletion in Observed Historical Hydrology and in Climate Change Hydrology • reflect natural lake effects on runoff routing • CIG has developed data, but Task 3.1 scope includes budget for possible revisions if necessary (relative to Considerations)

  25. Information from CIG  Task 3 • Transient • Preparing Inflow Data for Reservoir Simulation • Scenario Inflows need to: • reflect transient projection period = 150 years (1950-2099) • 1950-2008 is not to be confused with observed historical • 1950-1999 is ~statistically consistent with observed • historical sequencing aspects will differ, for each projection • reflect each model’s inflow definitions • Considerations: • basin depletion representation – see Hybrid • natural lake effects – see Hybrid • CIG has developed preliminary inflows data, but Task 3.1 is scoped for potential revisions (relative to Considerations)

  26. Extras – Texas Study(another Hybrid Example)

  27. Texas Study - Hybrid Example • Report • Prepard by CH2M-Hill • http://www.lcra.org/lswp/about/study/climatechange.html • Section 7.5 describes application of Hybrid Methodology

  28. Texas Study - Hybrid Example 1. 50-year Monthly Observed Distributions for a given grid cell…

  29. Texas Study - Hybrid Example 2. 31-year Monthly Simulated Distributions from a given projection for the same grid cell…

  30. Texas Study - Hybrid Example 3. Percentile-specific adjustments (sim - obs)

More Related