Scenario Methods for Climate Change Impacts Analysis. Modeling Support Branch Bay Delta Office

Transcription

1 Scenario Methods for Climate Change Impacts Analysis Modeling Support Branch Bay Delta Office Jamie Anderson Ph.D., P.E. CWEMF, Feb. 26, 2008

2 Acknowledgements Levi Brekke (Reclamation) Jay Lund (UCD) Noah Knowles (USGS) Ed Maurer (Santa Clara) David Purkey (SEI) Sebastian Vicuña (UCB) David Yates (NCAR) Chuck Young (SEI) 2

3 Governor s Executive Order EO S-3-05 June 1, 2005 Targets to reduce emission levels of Green House Gases Biennial reports starting Jan06 Water supply Public health Agriculture CA coastline Forestry Formed Climate Action Team 3

4 GCM Scenario based Impact Assessment Methodology SWP= State Water Project CVP=Central Valley Project 4

5 Analysis Options IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 5

6 GCM Scenario based Impact Assessment Methodology 6

7 Global Climate Modeling IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 7

8 GHG Emissions Scenarios A2 B1 IPCC 2001 Special Report on Emissions Scenarios (SRES) 8

9 GCM Simulations 20 th century through 2100 and beyond >20 GCMs Multiple Future Emissions Scenarios Emissions Scenarios Models 9

10 2008 CAT Team Scenarios 6 Global Climate Models GFDL-CM2.1 (USA) NCAR-PCM1 (USA) CNRM-CM3 (France) MPI-ECHAM5 (Germany) MIROC3.2med (Japan) NCAR-CCSM3 (USA) Two Emissions Scenarios A2 B1 high population growth regional economic growth fragmented technological changes low population growth rapid economic growth sustainable technology 12 Total Scenarios = 6 GCM x 2 Emissions Scenarios 10

11 GCM Scenario based Impact Assessment Methodology 11

12 Downscaling Comparison IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 12

13 Downscaling Convert Course GCM Data to Finer Scale Regional Data Bias Corrected Statistical Downscaling Analog Statistical Downscaling Compared by Ed Maurer (Santa Clara) & Hugo Hidalgo (Scripps) Maurer, E.P., H.G. Hidalgo, 2008, Utility of daily vs. monthly large-scale climate data: an intercomparison of two statistical downscaling methods, Hydrology and Earth System Sciences (in press) 13

14 GCM Scenario based Impact Assessment Methodology 14

15 VIC Model Features: Developed over 10 years Energy and water budget closure at each time step Multiple vegetation classes in each cell Sub-grid elevation band definition (for snow) Subgrid infiltration/runoff variability 3 soil layers used Non-linear baseflow generation VIC Model Slide a from Ed Maurer 15

16 National Weather Service California and Nevada River Forecast Center Calibrated to observed period SacSMA/Snow17 aka Sac Model 9 basins Upper basin Lower basin Modeled Basins 16

17 Rainfall Runoff Comparison IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 17

18 Runoff Ratios ( / Base): (a) SacSMA Runoff, Model Weather, (b) VIC Runoff, Model Weather Sacramento Slide from Levi Brekke 18

19 Bay-Delta Watershed Model (BDWM) Features Physically-based hydrologic model 4 km resolution Daily time step Simulates snowpack, streamflow, etc. Routes streamflow to points of interest Capable of ensemble, multi-decade simulations Slide from Noah Knowles, USGS Model developed with Kosta Georgakakos, Hydrologic Research Center, Del Mar, CA 19

20 Water Evaluation and Planning System WEAP Scalable Simulation Model Represents Physical hydrology Rainfall runoff Snow accumulation/melt Demands Agriculture M&I Environmental Water supply infrastructure Water quality (QUAL2K) Groundwater flow (MODFLOW) Well suited to study of infrastructure management within the context of climate change Inputs are downscaled climate predictions Temperature, precipitation, wind 20 Adapted from slides from Chuck Young

21 GCM Scenario based Impact Assessment Methodology 21

22 Impact Analysis Hydrologic Representation Perturbation method Ratio = Monthly Avg. Climate Change Value Monthly Avg. Historical Value Multiply historical time series by perturbation ratio Maintains historical patterns with varied magnitudes Unmodified output from rainfall-runoff model 22

23 Drought Analysis using WEAP Accumulated deficit from a dry condition based on Sacramento index Integrated nature of WEAP allows for changes in drought sequence unlike perturbation ratio approach Acumulated deficit from dry condition of Sacramento Index (TAF) 20,000 16,000 12,000 8,000 4, drought Early 90s drought Many sequential droughts One mega drought Year Historic GFDLB1 GFDLA2 PCMB1 PCMA2 Slide from Sebastian Vicuña 23

24 GCM Scenario based Impact Assessment Methodology 24

25 DWR & Reclamation IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 25

26 DWR & Reclamation IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 26

27 CALSIM II Schematic Statewide CVP & SWP Water Allocation Model State Water Project Central Valley Project Local 27

28 UC Davis IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 28

29 What is CALVIN? Model of entire inter-tied California water system Surface & groundwater systems; supply & demands Economics-driven optimization model Economic Values for Agricultural, Urban, & Hydropower Flow Constraints for Environmental Uses Prescribes monthly system operation over a 72-year representative hydrology Maximizes economic performance within constraints 29 Slide from Jay Lund

30 UC Berkeley and SEI IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 30

31 UC Berkeley and SEI IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 31

32 USGS IPCC = Intergovernmental Panel for Climate Change GCM = Global Climate Model SRES = Special Report on Emissions Scenarios, IPCC 2001 RFC= River Forecast Center 32

33 Similar Methodology Varied Applications 33

34 Similar Methodology Varied Applications Future Directions 34

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