Transcript Document
Applications of climate forecast information in water resources management: opportunities and challenges in the Yakima R. basin, Washington Andy Wood Julie Vano Shrad Shukla Anne Steinemann Civil and Environmental Engineering University of Washington NOAA Climate Prediction Application Science Workshop Chapel Hill, NC, March 2008 CPASW Challenge! Climatologically benign future meeting location? Using NOAA Climate Forecasts with Hydrological Assessments to Reduce Drought Vulnerabilities and Improve Water Management Project Goals: 1) Explore model-based hydrologic drought indicators as triggers for management: soil moisture, SWE, streamflow (Wood) 2) Interact with water users and managers to integrate climate and hydrologic forecasts in decisionmaking http://www.hydro.washington.edu/forecast/sarp/ (Steinemann) http://www.hydro.washington.edu/forecast/sarp/ Motivation • • • Drought among most costly natural disasters Drought in Washington agriculture losses more than $400 million in 2001 and $300 million in 2005 Climate and hydrologic forecast information helps avoid drought impacts Research Activities (2nd goal) • • Explore current uses of NOAA climate information in water resources management Understand user perspectives & decisions and identify service gaps Photo courtesy of http://www.usbr.gov/dataweb/html/yakima.html Linkages between Climate / Hydrologic Information and Decisions Examples decision water allocations for summer irrigation required information climate / hydrology on March 1, April-July runoff existing forecast information NRCS/RFC runoff volume forecast ENSO climatology set spawning flow levels; must keep constant by Nov 1, Nov-Dec inflow, precip or even just Nov 1-15 precip success / gap + accurate most years + easy to understand + location specific - no monthly disaggregation CPC medium range + shows direction of precipitation forecast; forecast clearly - no idea whether CPC seasonal they’re any good precipitation forecast - probability maps hard to translate to precip amts. Overview • Yakima River Basin hydrology and water use • Climate-related Decisionmaking Photo courtesy of http://www.usbr.gov/dataweb/html/yakima.html Yakima River Basin Hydrology • Elevation 8184 ft to 340 ft • Temp and precip 22-76F, 80-140 in at 2300 ft 90F, 0-10 in at 350 ft 60 - 80% precip in October-March • Water supply during growing season in lower basin primarily from snowmelt, depends on reservoirs for storage • Six USBR reservoirs with storage capacity of ~1 million acre-ft, ~25% unregulated runoff • Managed system vulnerable to drought with increasing water use and changing snowpack Climate Prediction Center Three-Month Outlooks Climate Division 74 http://www.cpc.ncep.noaa.gov/ Water Use in Yakima Basin - Agriculture -Yakima County 5th in nation Ag production -Higher value crops, less stress tolerant - Fisheries, spring and fall Chinook salmon, summer Steelhead, Coho salmon - Hydroelectric, nine power plants - Public water supply, population growth Photos courtesy of http://www.visityakima.com and http://www.wineyakimavalley.org Interactions with decisionmakers • Attend monthly USBR River Operations meetings • Understand how decisions made – people most involved – relevant meetings, reports, other resources • Understand current water management – Total Water Supply Available (50%, 100%, 150% of average) – uses of and impressions of forecasts – stigma of past events (eg, 2001, 1977) – major concerns for future Interactions with decisionmakers • Primary venue for face-toface interaction -- the monthly river operations meeting at the USBR Field Office in Yakima, WA. • Participants include: • forecasters • water managers • irrigation district managers • fisheries biologists • NRCS • Typical agenda at right Water management decisions have diverse climate information needs • Decision calendar helpful for organizing information (cf work by Andrea Ray, Bonnie Colby) – these vary by decisionmaker - e.g., Manager vs. Irrigator • Utility of forecasts (P, T, Q) varies greatly throughout the year • The following slides give several examples Spawning Flows vs Reservoir Refill (early November) decision made climate info considered Decision (by water manager): fix reservoir outflows to a constant during Nov-Dec so that fish can spawn without redds being flooded or dewatered; but keep as much water in storage so as to maximize future refill chances, up to the point of reducing flood control. Information needed: - system: current storage volume - hydrologic: system/channel inflows during Nov & Dec; Apr-July - climate: if hydrologic not available, precip during same periods Spawning Flows vs Reservoir Refill (early November) decision made climate info considered Information available: - system: current storage volume - hydrologic: Apr-Jul ESP forecasts from RFC (new, not connected yet); internal regressions - climate: CPC MR forecasts; CPC seasonal outlooks Gaps: - hydrologic: trusted, timely MR and Apr-Jul forecasts at relevant sites - climate: gap may be smaller than expected Spawning Flows vs Reservoir Refill (early November) Climate Information Use Use depends on current situation – in general, if a decision outcome uncertainty range includes adverse consequences, more information is sought. For example, system storage is a critical factor. - Storage good – no worries. - Storage low – both MR and seasonal forecasts become “of interest”. MR forecasts are trusted more, and used as qualitative “tie-breaker” Seasonal forecasts are perused, not really trusted. Seen as “directionally deterministic”. directional determinism Decisions may depend on short, medium range and seasonal forecast information at once Basin outflow Yakima system storage The sources of information at different leads are distinct… one event but decisionmakers intuitively weight and merge information An argument for the so-called “seamless suite”! climate/hydrology decision areas increasing carryover while preparing to support flows for fish in fall week-to-week operations in summer e.g. climate/hydrology decision areas agricultural decisions in winter for irrigation season Managers: taking an early look at water year, but can’t make public statements until March. Farmers / irrigators / banks: what to plant, $ from banks, water trading decisions. Gaps? Climate: CPC/WFOs do have forecast products in the realms that this USBR needs, and USBR accesses them. No use of “skill” information intuitive weighting by USBR Hydrology: RFCs/NRCS have a few flow products that meet USBR needs, but some connections have not been made. No use of “skill” information intuitive weighting use of multiple sources to assess confidence Observed Observed AN AN 19% 10% 2% 71% Temperature AN 69% BN 28% 30% BN BN Forecast AN BN Forecast Accuracy, usefulness, and limitations of forecast information 22% 20% 48% Precipitation • Directional Skill: What percentage of time is the forecast in the "right" direction? Above Normal (AN) or Below Normal (BN) • CPC Seasonal Forecast Climate Division 74, lead time 0.5 month, 1995-2006 • Temp more skillful than precip according to this measure use of analogues…an opportunity? analogue “forecast” use is widespread in applications world. i.e., this year is like … pros: no “median” line lots of variability can relate directly to past experience cons: can under-represent variability hard to combine with ICs Preliminary Conclusions • NOAA medium range and seasonal climate forecasts are needed in typical western water management • Users consider NOAA forecasts in decisionmaking despite a lack of information on their skill • Seasonal forecasts a much greater target of skepticism than medium range forecasts • “Re-findings”: deterministic interpretations; resolution (temporal / spatial) too coarse for quantitative use. • opportunities in communication: e.g., analogues, hidden products Future Directions • continue to interact and explore matches between forecast information and management decisions • extend analyses to hydrologic forecasts, hopefully with participation from NW RFC. Acknowledgements COLLABORATORS - Chris Lynch, US Bureau of Reclamation - Doug McChesney, WA Dept of Ecology FUNDING - NOAA Sector Applications Research Program (SARP) - University of Washington Presidential Fellowship (Vano) Questions? Andy Wood [email protected] [email protected] Julie Vano [email protected] Shrad Shukla [email protected] Anne Steinemann [email protected]