alan f. hamlet jisao/cses climate impacts group dept. of civil and environmental engineering...
Post on 13-Dec-2015
213 Views
Preview:
TRANSCRIPT
Alan F. Hamlet •JISAO/CSES Climate Impacts Group•Dept. of Civil and Environmental Engineering
University of Washington
Effects of Projected Climate Change on the Hydrology of the Puget Sound Region and Potential Impacts to Puget Sound
Image Credit: National Snow and Ice Data Center, W. O. Field, B. F. Molniahttp://nsidc.org/data/glacier_photo/special_high_res.html
Aug, 13, 1941 Aug, 31, 2004
Recession of the Muir Glacier
1) Modeling experiments reproduce
history of global temperatures
remarkably well.
2) Natural forcings (e.g. volcanic eruptions and variations in solar radiation) alone cannot explain the rapid rise in temperature at the end
of the 20th century.
Global Climate Change Scenarios for the PNW
Mote, P.W. and E. P. Salathe Jr., 2010: Future climate in the Pacific Northwest, Climatic Change, DOI: 10.1007/s10584-010-9848-z
21st Century Climate Impacts for the Pacific Northwest Region
Seasonal Precipitation Changes for the Pacific Northwest
http://cses.washington.edu/db/pdf/wacciach1scenarios642.pdf
Projected sea level rise in Puget Sound relative to 1980-99
http://cses.washington.edu/db/pdf/moteetalslr579.pdf
?
Hydrologic Projections
http://www.hydro.washington.edu/2860/
HydrologicProducts
Draft
Snow Model
Schematic of VIC Hydrologic Model and Energy Balance Snow Model
Watershed Classifications:Transformation From Snow to Rain
Map: Rob Norheim
Effects to Rain Dominant Basins:
Chehalis River near Grand Mound
SWE Runoff
Mixed Rain and Snow (Warm):
Nisqually River at La Grande Dam
SWE Runoff
Mixed Rain and Snow (Colder):
Snohomish River Near Monroe
Mild Snowmelt-Dominant Basins:
Skagit at Mount Vernon
SWE Runoff
HumanHuman HealthHealth
Agriculture/EconomicsAgriculture/Economics
SalmonSalmonForest ResourcesForest Resources
CoastsCoasts EnergyEnergy
InfrastructureInfrastructure
Water ResourcesWater Resources
A comprehensive climate change
impacts assessment for Washington State
AdaptationAdaptation
http://cses.washington.edu/db/pdf/wacciaexecsummary638.pdf
Washington State Climate Change Impacts Assessment
Executive Summary:
Changes in Hydrologic Extremes
Summary of Flooding Impacts
Rain Dominant Basins:Possible increases in flooding due to increased precipitation intensity, but no significant change from warming alone.
Mixed Rain and Snow Basins Along the Coast:Strong increases due to warming and increased precipitation intensity (both effects increase flood risk)
Inland Snowmelt Dominant Basins:Relatively small overall changes because effects of warming (decreased risks) and increased precipitation intensity (increased risks) are in the opposite directions.
2040s Changes in Flood RiskSkagit River at Mount Vernon
A1B B1
Historical10 Member Ensemble Using the Hybrid Delta Downscaling Approach
Recession of Whitechuck Glacier(Sauk Headwaters)
1973 2006
Photos courtesy of Dr. Mauri Pelto, Nichols College
Mass Balance of the Nisqually Glacier
http://faculty.washington.edu/scporter/Rainierglaciers.html
Loss of glacial mass may maintain or even increase summer flow in the short term but
is expected to decrease summer flow in the long term.
19101910 19301930 19501950 19701970 19901990 2010201000
1.01.0
2.02.0
3.03.0
4.04.0
5.05.0
6.06.0
YearYear
8.08.0
7.07.0
19991999
20012001
20002000
20032003
20022002
Ann
ual a
rea
(ha
× 1
06 ) a
ffect
ed b
y M
PB
in B
CA
nnua
l are
a (h
a ×
106 )
affe
cted
by
MP
B in
BC
200520059.09.0
20042004
Bark Beetle Outbreak in British Columbia
(Figure courtesy Allen Carroll)
Sediment Transport
Sediment Impact Pathways:
Increasing precipitation intensity may increase the severity of extreme events (e.g. mud slides, inundation of public access areas, etc.)
Loss of glaciers may mobilize large “reservoirs” of sediment stored beneath them.
Loss of snowpack may reduce the “armoring” effect of the snowpack in moderate elevation areas, leading to increased land slide risk and increased sediment loadings. (conversion of moderate elevation areas from avalanche risk to land slide risk).
Changes in forest disturbance patterns, particularly fire, may be important driver of impacts.
http://www.abbegeomorphology.com/?p=69
Sediment Impacts in the Nisqually Headwaters
Effects to Stream Temperature
Mantua, N., I. Tohver, A.F. Hamlet, 2010: Climate change impacts on streamflow extremes and summertime stream temperature and their possible consequences for freshwater salmon habitat in Washington State,
Climatic Change, online first, doi: 10.1007/s10584-010-9845-2
7Q10 values are projected to
systematically decline in western WA due to loss of snowpack and
projected dryer summers
Changes in Low Flows
Mantua, N., I. Tohver, A.F. Hamlet, 2010: Climate change impacts on streamflow extremes and summertime stream temperature and their possible consequences for freshwater salmon habitat in Washington State, Climatic Change, doi: 10.1007/s10584-010-
9845-2
Nicholls, R. J. and Cazenave, A. (2010) Sea-Level Rise and Its Impact on Coastal Zones. Science 328, 1517-1520
Sea Level Rise
•Anticipate changes. Accept that the future climate will be substantially different than the past.
•Use scenario based planning over long time scales to evaluate options rather than the historical record.
•Expect surprises and plan for flexibility and robustness in the face of uncertain changes rather than counting on one approach.
•Plan for the long haul. Where possible, make adaptive responses and agreements “self tending” to avoid repetitive costs of intervention as impacts increase over time.
Approaches to Adaptation and Planning
top related