Transcript hamlet_awwarf_c_mar_2004

Strategies for Water Planning in an
Uncertain Climate
JISAO/SMA Climate Impacts Group
and Department of Civil and Environmental Engineering
University of Washington
March, 2004
Alan F. Hamlet
People in the Climate Impacts Group
PI: Edward L. Miles (human dimensions)
Principals:
Robert Francis (aquatic ecosystems)
Dennis P. Lettenmaier (hydrology and water resources)
Nathan Mantua (climate dynamics)
Philip W. Mote (state climatologist)
Lara Whitely Binder (education and outreach)
Richard Palmer (water resources management)
David L. Peterson (forests)
Amy K. Snover (integration and synthesis)
Example of a flawed water planning study:
The Colorado River Compact of 1922
The Colorado River Compact of 1922 divided the
use of waters of the Colorado River System
between the Upper and Lower Colorado River
Basin. It apportioned **in perpetuity** to the
Upper and Lower Basin, respectively, the
beneficial consumptive use of 7.5 million acre feet
(maf) of water per annum. It also provided that the
Upper Basin will not cause the flow of the river at
Lee Ferry to be depleted below an aggregate of
7.5 maf for any period of ten consecutive years.
The Mexican Treaty of 1944 allotted to Mexico a
guaranteed annual quantity of 1.5 maf. **These
amounts, when combined, exceed the river's
long-term average annual flow**.
Education
CIG
Outreach
Partnerships
Stakeholders
Planning Partnerships
• Seattle Public Utilities
• Portland Water Bureau
• Northwest Power and Conservation Council
• Idaho Dept. of Water Resources
CIG Annual Water Workshops
http://jisao.washington.edu/PNWimpacts/Workshops/Kelso2003/index.htm
Critical Period Planning Methods for Water Studies
Columbia River at The Dalles
1934
1934
1933
1933
1932
1932
1932
1931
1931
1930
1930
1930
1929
1929
1928
1928
1927
1927
1927
1926
1926
1925
1925
1925
800000
700000
600000
500000
400000
300000
200000
100000
0
Observed Streamflows
Planning Models
System Drivers
Incorporating Climate Change in Critical Period Planning
Long term planning for climate change may include a stronger
emphasis on drought contingency planning, testing of preferred
planning alternatives for robustness under various climate change
scenarios, and increased flexibility and adaptation to climate and
streamflow uncertainty.
Observed Streamflows
Planning Models
Altered Streamflows
Climate Change Scenarios
System Drivers
Changes in Mean
Temperature and
Precipitation or Bias
Corrected Output
from GCMs
VIC
Hydrology Model
ColSim
Reservoir
Model
The main impact: less snow
VIC Simulations of April 1 Average Snow Water Equivalent
for Composite Scenarios (average of four GCM scenarios)
Current Climate
2020s
Snow Water Equivalent (mm)
2040s
Naturalized Flow for Historic and Global Warming Scenarios
Compared to Effects of Regulation at 1990 Level Development
Historic Naturalized Flow
Estimated Range of
Naturalized Flow
With 2040’s Warming
Regulated Flow
Effects to the Cedar River (Seattle Water Supply)
for “Middle-of-the-Road” Scenarios
9000
8000
6000
Simulated 20th
Century Climate
2020s Climate
Change Scenario
2040s Climate
Change Scenario
5000
4000
3000
2000
1000
Date
9/2
8/5
7/8
6/10
5/13
4/15
3/18
2/18
1/21
12/24
11/26
10/29
0
10/1
Inflow (acre-ft)
7000
Web-Based Data Archive
http://www.ce.washington.edu/~hamleaf/climate_change_streamflows/CR_cc.htm
Climate Change May Exacerbate Other
Impacts
Exceedance
Probabilityof
of Reduced
the
Exceedance
Probability
Difference
in Annual
Storage
less Shortfalls
Storage
Value Minimum
from Current
Climate
and
from Current Climate and 2000 Demands
2000 Demands
Current Climate / 2040 Demands
ECHAM4 2040 / 2000 Demands
ECHAM4 2040 / 2040 Demands
11,000
climate
change
and
growth
10,000
9,000
Million Gallons
8,000
7,000
6,000
5,000
growth
4,000
3,000
climate
change
2,000
1,000
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Exceedance Probability
0.8
0.9
1
Climate change adaptation may involve complex tradeoffs
between competing system objectives
Percent of Control Run Climate
2070-2098
140
PCM Control Climate and
Current Operations
120
PCM Projected Climate
and Current Operations
100
PCM Projected Climate
with Adaptive
Management
80
60
Firm
Hydropower
Annual Flow
Deficit at
McNary
Source: Payne, J.T., A.W. Wood, A.F. Hamlet, R.N. Palmer and D.P. Lettenmaier, 2004, Mitigating the
effects of climate change on the water resources of the Columbia River basin, Climatic Change (in press).
There may be thresholds associated with impacts
Water supply timing changes estimated to occur by 2020 are
handled by the storage and allocation system with little shortage
change. However, the modeled reductions in water amount by 2040
would produce much more significant irrigation water shortages.
These results could be made worse by changes in water demand.
Sources of Uncertainty
Problems with potentially biased spatial patterns in free running GCMs
Do free running GCMs accurately reproduce the position of dominant
storm tracks for particular regions?
How far can GCM output be downscaled if the position of the storm track
is unrealistic or biased?
Snake gets wetter
Snake gets drier
Current
Future
Current
Future
Effects of the PDO and ENSO on Columbia River
Summer Streamflows
PDO
450000
Cool
Cool
Warm
Apr-Sept Flow (cfs)
400000
Warm
350000
300000
250000
200000
high
high
low
low
Ocean Productivity
2000
1990
1980
1970
1960
1950
1940
1930
1920
1910
1900
150000
Trends in Annual Streamflow at The Dalles from 1858-1998 are strongly downward.
350000
250000
Annual
200000
5 yr mean
10 yr mean
150000
Linear (Annual)
100000
50000
0
1858
1868
1878
1888
1898
1908
1918
1928
1938
1948
1958
1968
1978
1988
1998
Annual Mean Flow (cfs)
300000
Log10 mean flow, The Dalles, OR (cfs)
The Dust Bowl was probably not the worst drought sequence
in the past 250 years
5.5
red = observed, blue = reconstructed
5.4
5.3
5.2
5.1
5.0
1750
1775
1800
1825
1850
1875
Year
1900
1925
1950
1975
Source: Gedalof, Z., D.L. Peterson and Nathan J. Mantua. (in review). Columbia
River Flow and Drought Since 1750. Submitted to Journal of the American
Water Resources Association.
2000
Role of Monitoring in Scenario Validation
20th century decline in NH snow cover
Surface measurements
Satellite meas.
R.D. Brown, J. Climate, 2000
Trends in April 1 snow water equivalent, 1950-2000
Source: Mote et al. (2004)
Snowmelt runoff timing trends, 19482000
Graphic provided by Dan Cayan, Scripps Institute of Oceanography and the
USGS. To appear in Climatic Change, 2003
Some Broad-Based Management Alternatives
Supply Side
Increase conventional storage
Build new storage projects
Enlarge existing storage projects
Off-stream surface water storage projects
Ground water storage and recharge
Advanced waste water treatment systems (Yelm, WA)
Reverse osmosis in coastal areas
Improve forecasting systems and management
Demand Side
Conservation and plumbing codes
Pricing of water to reflect scarcity and demand
Market based transfers and water banks
Approaches and Criteria for Identifying Preferred
Management Alternatives and Robust Planning Strategies
1) Identify the components of the planning process that are sensitive or insensitive
to climate uncertainties
2) Identify planning alternatives that are acceptable and robust to different climate
scenarios, even if they are perhaps not optimal under all climate scenarios
3) If no one plan is best under all climate scenarios, then identifying which plan is
best for each scenario may be helpful in assessing the ability to respond to
evolving conditions.
4) Identify alternatives that are more flexible than others in the sense that they can
be substantially altered as uncertain conditions evolve. Such plans may be
preferable if the water system is very sensitive to altered climate (and particularly
uncertain projections of precipitation variability).
5) Identify plans that have "irreversible" components (e.g. because of investment in
infrastructure or other capital expenditures). Such plans may in some cases
increase future risks and reduce response capability.
6) Identify "no regrets" strategies that create desirable outcomes regardless of
uncertainties. (e.g. improve communication drought planning)
7) Identify management alternatives or planning strategies that are “self tending”
and evolve dynamically without recursive policy intervention. (e.g. water markets
or water pricing mechanisms)
Selected References and URL’s
Climate Impacts Group Website
http://jisao.washington.edu/PNWimpacts/Infogate.htm
White Papers, Agenda, Presentations for CIG 2001 Climate Change Workshop
http://jisao.washington.edu/PNWimpacts/Workshops/Skamania2001/WP01_agenda.htm
Climate Change Streamflow Scenarios for Water Planning Studies
http://www.ce.washington.edu/~hamleaf/climate_change_streamflows/CR_cc.htm
Refs on Climate Variability and Climate Change
http://www.ce.washington.edu/~hamleaf/hamlet/publications.html