Applications of climate forecast information in water resources

management: opportunities and challenges in the Yakima R. basin,

WashingtonAndy Wood

Julie VanoShrad Shukla

Anne Steinemann

Civil and Environmental EngineeringUniversity 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

http://www.hydro.washington.edu/forecast/sarp/

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 decision-making(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

Photo courtesy of http://www.usbr.gov/dataweb/html/yakima.html

Research Activities (2nd goal)• Explore current uses of

NOAA climate information in water resources management

• Understand user perspectives & decisions and identify service gaps

decisionrequired informationclimate / hydrology

existing forecastinformation success / gap

water allocations forsummer irrigation

on March 1, April-July runoff NRCS/RFC runoff volume forecast

ENSO climatology

+ accurate most years+ easy to understand+ location specific- no monthly disaggregation

set spawning flowlevels; must keepconstant

by Nov 1, Nov-Dec inflow, precipor even just Nov 1-15 precip

CPC medium rangeprecipitation forecast;

CPC seasonalprecipitation forecast

+ shows direction of forecast clearly

- no idea whether they’re any good- probability maps hard to

translate to precip amts.

Linkages between Climate / Hydrologic Information and DecisionsExamples

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 ft90F, 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 CenterThree-Month Outlooks

Climate Division

74

http://www.cpc.ncep.noaa.gov/

- 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

Water Use in Yakima Basin

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-to-face 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 (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

decisionmade climate info considered

Spawning Flows vs Reservoir Refill(early November)

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

decisionmade climate info considered

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

The sources of information at different leads are distinct…

but decisionmakers intuitively weight and merge information

An argument for the so-called “seamless suite”!

one event

Yakima system storage

Basin outflow

increasing carryover while preparing to support flows for fish in fall

week-to-week operations in summere.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.

climate/hydrology decision areas

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

Accuracy, usefulness, and limitations of forecast information

• 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

ObservedAN BN

Fo

rec

as

tB

N

A

N

69% 19%

10% 2%

Temperature

ObservedAN BN

Fo

rec

as

tB

N

A

N

Precipitation

28% 30%

22% 20%

48%71%

use of analogues…an opportunity?analogue “forecast” use is widespread in applications

world.i.e., this year is like …

pros:

no “median” linelots of variabilitycan 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 Woodawood@3tiergroup.com aww@u.washington.edu

Julie Vanojvano@u.washington.edu

Shrad Shuklashrad@hydro.washington.edu

Anne Steinemannacstein@u.washington.edu