Climate Change and Water
Michael J. Furniss
Pacific Northwest and Pacific Southwest
Research Stations
Redwood Sciences Lab
Arcata, CA
Acknowledgements
Connie Millar, Cindy Miner, Sherry Hazelhurst, Brian Staab, Ken Roby, Al Todd, Beth Larry, Caty Cifton, Dave Peterson, Linda Joyce, Leslie Reid, Gordon Grant, Kelly Redmond, Dan Isaaks, Nate Mantua, Jim Sedell, Robin Tausch…
For inspiration, guidance, ideas, slides, and graphics
The last “big bang”
New
Old
• Activities must be
compatible with
Ecosystem Objectives
• Activities occur unless
unacceptable impacts
occur
• Focus is on Watershedscale/processes
• Focus is on sitescale/conditions
• Coordinated, cooperative
management
• Independent
management unless
problems occur
Watershed Restoration Program
“New vs. “Old”
New
• Secure the “best” first
Old
• Treat the “worst” first
• Watershed-scale analysis • Project/site-scale analysis
and treatment
and treatment
•
Integrated treatments”ridge to ridge”
• Partners/leveraged
funding essential
• Independent treatmentsin-stream focus
• Partnerships/leveraged
funding optional
Where do NF activities come from?
Old
•
•
•
•
•
Programs
Proposals
PSQ
Plans
People’s preferences
New
• Place
• Potentials and Needs
• Perplexities
Simultaneous multi-disciplinary
Real interdisciplinarity
Lessons (sorta) Learned
• Ecosystem management requires multiscale assessment. Top down.
• Intermediate-scale analysis:
– Brings together context and detail
– Hard
– Most important
Lessons (sorta) Learned
• If analysis is not required, it does not
happen.
• New thinking needs renewal.
Watershed Vulnerability
Assessment
• How will changing climates affect the watersheds on my beat? • Elevation, snow storage
• How water is stored
• Rain‐on‐snow
• Affected aquatic and riparian habitats
• Values at risk
• Demands downstream
• Threats (fire, insects, OHVs, disease)
• Ability to manage for outcomes
• Most appropriate monitoring
• and so on Changes are Certain
But
Timing, Magnitude, Duration, Frequency and Location of changes is highly uncertain and, for many projected changes, highly variable.
Basics of Watershed Stewardship are Still Sound
But the stakes get higher.
Resilient watersheds are a prudent response to CC
Models: Due Caution?
3 purposes
1. Understanding elements of the problem
2. Playing “what ifs”
3. Operational decision-making
Water, Climate Change, and the
Forest Service
Projected changes to the hydrologic cycle
Drier vegetation and
soils. Increased
wildfires and area
burned
More rain and less snow.
Snow melts sooner in
Spring
More intense storms with
more flooding and
extreme winds
Glaciers are reduced or
eliminated. Increased
high elevation erosion.
Sea level rises. More
coastal erosion.
Saltwater intrusion into
coastal freshwater
aquifers
Earlier spring runoff.
Larger flood peaks. Less
summer stream flow.
Smaller headwater
stream network
March 10, 2004
70”
55”
12”
7.5”
Slide from Kelly Redmond
Projected patterns of precipitation changes
(2090-2099)
(IPCC 2007)
winter
summer
Climate models consistently show ~10 to 30% increases in high latitude summer and winter precipitation; for mid‐latitudes, winter precipitation increases ~10% while summer precipitation changes are more regional (and less consistent between models)
What Changes? More extremes
More heat in global weather system = intensification of weather and climatic extremes. • Floods
• Droughts
• Wind
• Heat waves
• More variability
QuickTime™ and a
decompressor
are needed to see this picture.
Stationarity is Dead
QuickTime™ and a
decompressor
are needed to see this picture.
CLIMATE CHANGE: Stationarity Is Dead: Whither Water Management?
P. C. D. Milly,1* Julio Betancourt,2 Malin Falkenmark,3 Robert M.
Hirsch,4 Zbigniew W. Kundzewicz,5 Dennis P. Lettenmaier,6 Ronald J.
Stouffer7
PNW
Sierra
Nevada
(McCabe & Wolock, 1999)
Flow (x 1000 acre-feet)
Hydrologic Regimes
Lettenmaier and Gan 1990
Changes in Context
•
Climate changes are cumulative effects and all changes of concern must be viewed in the context of cumulative effects.
Grant and Lewis
wet year
average year
dry year
Small catchments
Even a small reduction in
low flow discharge can
result in a large decrease in
stream length
total
august
stream
length
annual precipitation
Compounding Effects: As streamflows Compounding Effects
diminish, stream networks contract, increasing risk to headwater species
Couples with increasing stream temperatures, more sediment from fires, more demand for withdrawls, more rain‐on‐snow flooding, larger spring floods, and so on…
Disturbance Regimes are Changing.
Unconfined
Valley Bottom
Reservoir operations?
•
•
•
•
•
More aquatic ecosystem stresses
More flood probability
More water demand
Less snow‐mediation of runoff
More societal need for hydropower
North Coast Climate Refuge?
• Projected warming decreases as you go west and
approach the Pacific (+2-3oC vs 8+ in the interior of the continent (p. 890)
• Projected warming is less at lower elevations
• Substantial excess moisture recharge for soils
• Little dependence on snowpack
• More summer fog
– Inland heat
– Wind/upwelling models suggest more upwelling
• Coastal – SLR hurts...but we don’t have much
development near sea level
North Coast
Inundation with
1 m of sea level
rise.
Use Scenario Planning
• Set a range of plausible futures
• Evaluate risks and potentials against each scenario
• Pre‐made scenarios might be called for. What if the 100‐year flood becomes the 25‐year flood? The 10‐year flood?
What now? Fix Road Problems & Risks
Water Moved = Carbon Emissions
• Hydropower
• Moving water is very expensive
• Environmental mitigations –
Willamette
Dams are in
• Water storage
• Non‐coal electricity
• Smaller, more local? Keeping water in the land longer
Meadow and valley bottom restoration can increase the natural reservoir, augment dry‐
season baseflows, and many other benefits.
More, larger wet places in a warming, drying landscape
Mountain meadows and valley bottoms are reservoirs.
The quantity of stored water is immense
The Natural Reservoir We Manage
FIGURE XX: HYDROLOGIC EFFECTS OF MEADOW “PLUG AND
POND” RESTORATION
a) Incised meadow before restoration:
Eroded alluvium
Lost groundwater storage
Original meadow
surface
Water table
Pre-restoration
groundwater
storage
Bedrock
Incised channel
FIGURE XX: HYDROLOGIC EFFECTS OF MEADOW “PLUG AND
POND” RESTORATION
b) Restored meadow:
Plugged gully
Restored channel
Water table
Restored groundwater storage
Pre-restoration
groundwater storage
Bedrock
Knowledge
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WVA
EFRs
River gauging
Snow sensing
Soil Moisture Monitoring
Prediction
Understanding
Teaching
Climate Change Resource Center
www.fs.fed.us/ccrc