forests, water & research in the sierra nevada
DESCRIPTION
Forests, water & research in the Sierra Nevada. Roger Bales, Sierra Nevada Research Institute, UC Merced. Sierra Nevada watershed research infrastructure . MODIS image. Elev., m. E-W transect of flux towers. 3000. 2400. 1800. 1200. 600. Shorthair Creek 2700 m 8900 ft. - PowerPoint PPT PresentationTRANSCRIPT
Forests, water & research in the Sierra Nevada
Roger Bales,Sierra Nevada
Research Institute, UC Merced
CZO
N-S transect of research catchments
MODIS image
Main CZO site
6001200180024003000
Elev., m
San Joaquin Experimental
Range400 m1300 ft
Shorthair Creek
2700 m8900 ft
CZO P301
2000 m6600 ft
Soaproot Saddle1100 m3600 ft
E-W transect of flux towers
Southern Sierra Critical Zone Observatory
Sierra Nevada watershed research infrastructure
infiltration
evapotranspiration
snowmelt
runoff
sublimation
ground & surface water exchange
precipitation
Mountain hydrology – fluxes
Reservoirs: Snowpack storageSoil-water storage
How will this landscape & the hydrologic processes connecting it alter w/ climate warming & land-use/landcover change?
Motivating questions
infiltration
evapotranspiration
snowmelt
runoff
sublimation
ground & surface water exchange
precipitation
Mountain hydrology – fluxes
Reservoirs: Snowpack storageSoil-water storage
Myth:
We can, with a high degree of skill, estimate or predict the magnitude of these quantities
infiltration
evapotranspiration
snowmelt
runoff
sublimation
ground & surface water exchange
precipitation
Mountain hydrology – fluxes My biases:Improved predictions
require better process understanding
The basis for process understanding is new measurements
Processes are coupled & best studied together
Reservoirs: Snowpack storageSoil-water storage
Basic water balancePrecipitation = Evapotranspiration + Runoff
= +
0.1 increase per 350 m (1150 ft)
Decreasing temperatureIncreasing snow fractionDecreasing vegetationCoarser soils
3oC
6000’ 8000’7000’
5oF 50% more runoff in snow dominated vs. mixed rain-snow catchments
Implication for 2oC warmer climate:Reduce runoff by 10-40% in mixed conifer forest (assuming ecosystems adapt)
Elevation (m)
0 1000 2000 3000
ET
(mm
yr-1
)
300
400
500
600
700
800
GP
P (gC
m-2 yr -1)
600
800
1000
1200
1400
1600
1800
2000
Mean ET Tower-based ET (2009-11)Mean GPP
2010
2010
2010
2011
20112011
2011
2009
mm in
800 32
700 28
600 24
500 20
400 16
300 12
0 1000/ 2000/ 3000/ 3300 6600 10000
Elevation, m/ft
Goulden et al., submitted
Annual evapotranspiration
– Highest current evapotranspiration in rain to rain-snow transition region of mixed conifer forest – year-round growth
– Lower elevation is water limited– Higher elevation is cold limited
Sierra Nevada precipitation & snow water equivalent (SWE) – climatological estimate?
in>80
705035251510
in
>28
24
16
8
3
Most snowmelt comes from
elevations above most measurement of precipitation or
snowpack
Mountain water cycle & climate warmingLand surface temperatures
5-yr average Departure from 1901-2000 mean
Warming by 2–6oC (4–11oF) drives significant changes:
– rain-vs-snow storms *– snowpack amounts *– snowmelt timing *– flood risk– streamflow timing *– low baseflows– growing seasons *– recharge?– drier soil in summer
Precipitation changes uncertain
Already observed (*)
2
1
0
-2
-1
oF
oF15
11
7
4
0
-4
Kings basin snowmelt w/ climate warming
Making a water-secure world – the three I’s
Better & more-accessible
INFORMATION
INFRASTRUCTURE to store, transport
& treat water
Stronger & more-adaptable
INSTITUTIONS
Water security: the reliable availability of an acceptable quantity & quality of water for health, livelihoods & production, coupled w/ an acceptable level of water-related risks
Ecosystem services
Making a water-secure world – the three I’s
Better & more-accessible
INFORMATION
INFRASTRUCTURE to store, transport
& treat water
Stronger & more-adaptable
INSTITUTIONS
Water is fundamental to sustainable ecosystem services. Water management therefore translates into managing ecosystem services, and must be a fundamental goal of virtually all such efforts.
lidar
A new generation of integrated measurements
eddy correlation
satellite snowcover
embedded sensor
networks
isotopes & ions
sap flow
low-cost sensors
sediment
Basin-wide deployment of hydrologic instrument clusters – American R. basin
Strategically place low-cost sensors to get spatial estimates of snowcover, soil moisture & other water-balance components
Network & integrate these sensors into a single spatial instrument for water-balance measurements.
Building the knowledge base to enhance forest & water management