columbia river basin water supply and irrigation demand forecast for the 2030s jennifer c. adam,...
TRANSCRIPT
Columbia River Basin Water Supply and Irrigation Demand Forecast for the 2030s
Jennifer C. Adam, Assistant ProfessorCivil and Environmental EngineeringWashington State University
WSU Modeling TeamCivil and Environmental Engineering / State of Washington Water Research CenterJennifer Adam, Assistant ProfessorMichael Barber, Professor and Director of SWWRCKiran Chinnayakanahalli, Postdoctoral AssociateKirti Rajagopalan, PhD StudentShifa Dinesh, PhD StudentMatt McDonald, MS Student
Biological Systems EngineeringClaudio Stöckle, Professor and ChairRoger Nelson, Research AssociateKeyvan Malek, PhD Student
School of EconomicsMichael Brady, Assistant ProfessorJon Yoder, Associate ProfessorTom Marsh, Professor and Director of IMPACT Center
Center for Sustaining Agriculture and Natural ResourcesChad Kruger, DirectorGeorgine Yorgey, Research Associate
Background
The economic, ecologic, and cultural well being of Washington's Columbia River Basin depends on water
Irrigation largest water user
Economic value of agriculture (5 billion $ in WA)
Water resources sensitive to climate change
Better understanding of future range in supply and demand needed to guide investment decisions
Predicted Climate Changes
Temperature Annual temperature increase (0.2 to 1.0°F /
decade) Summer increases are greater than other
seasons Precipitation
Annual precipitation: less agreement among Global Climate Models (small on average: +1 to +2%)
Summer precipitation decreases; other seasons increase
Net Result: shifting of water availability away from summer season of peak irrigation water demand
Goals
To project 2030s water supply and (agricultural and municipal) demand in the Columbia River Basin
WA Dep. of Ecology Report to State Legislature (November, 2011)
Linked WSU Study Components
1. Biophysical modeling of historical and future water supply and irrigation demand
2. Municipal Demand Forecast
3. Hydropower Review
4. Regional survey of Columbia River Basin water managers
5. Economic analyses of domestic and international factors driving agricultural production
6. Outreach
Unique Aspects of Approach:*Integration of Surface Hydrology and Cropping Systems*Incorporation of Water Management (Reservoirs and Curtailment of Interruptible Irrigation Rights)*Integration with Economic Modeling
Modeling Framework
Models Used
VIC Hydrology
Liang et al, 1994
CropSystCropping Systems
Stockle and Nelson 1994
VIC-CropSyst Model
1. Weather (D)
2. SoilSoil layer depths
Soil water content
3. Water flux (D)Infiltrated water
4. Crop type
Irrigation water = Crop Water Demand
/irrigation efficiency
Sow dateCrop interception
capacityCrop phenologyCrop uptake (D)Water stress (D)
Current biomass (D)Crop Water demand
(D)Harvest dayCrop Yield
VIC CropSyst
D – communicated daily
Crops Modeled
Winter Wheat Spring Wheat Alfalfa Barley Potato Corn Corn, Sweet Pasture Apple Cherry Lentil Mint Hops
Grape, Juice Grape, Wine Pea, Green Pea, Dry Sugarbeet Canola
Onions Asparagus Carrots Squash Garlic Spinach
Generic Vegetables
Grape, Juice Grass hay Bluegrass Hay Rye grass
Oats Bean, green Rye Barley Bean, dry Bean, green
Other Pastures
Lentil/Wheat type
Caneberry Blueberry Cranberry
Pear Peaches
Berries
Other Tree fruits
Major Crops
Overview of Framework
VIC
I. Coupled simulation of
hydrologic cycle and crop growth:
all irrigation requirements met
II. Runoff, baseflow, and return flow routed through
flow network; reservoir simulation accounts for
irrigation diversions
III. Irrigation and municipal diversions compared to water
availability and instream flow requirements;
curtailment in dry years
IV. Iteration of coupled simulation
to account for reduced irrigation in
dry years
ColSim
Biophysical Modeling:VIC-CropSyst, Reservoirs,
Curtailment
• Crop Yield
• Irrigation Water Applied
• Adjusted Crop
Acreage
• Selective Deficit
Irrigation
1. Water Supply2. Irrigation Water
Demand3. Unmet Irrigation
Water Demand4. Effects on Crop
Yield
Economic Modeling:Agricultural Producer
Response
Water Management Scenario
Future Climate Scenario
Inputs Modeling Steps Outputs
Integration with Economics
Economic Scenario
Model Scenarios: Low, Middle, High Climate Change (Biophysical) Scenarios
Precipitation changes Temperature changes
Water Management Scenarios Additional Storage Capacity Cost Recovery for Newly Developed Water
Supplies Economic Scenarios
Trade Economic Growth
Supply is also shown for wet, dry, and average conditions
1. Columbia Basin-Scale and Columbia Mainstem
2. Example Watershed-Scale: Yakima
Results
Water Supply Entering
Washington• Eastern: increasing• Western: decreasing
Top: 2030 Flow (cfs)Bottom: Historical Flow (cfs)
Water Supply Entering Columbia Mainstem
• Eastern: increasing• Western: decreasing
Top: 2030 Flow (cfs)Bottom: Historical Flow (cfs)
Snake River and Columbia River Supplies
Snake River Columbia River
Regulated Supply vs Demand for Columbia River Basin (at Bonneville)
2030 results are for- HADCM_B1 climate scenario- average economic growth and trade
Note: Supply is reported prior to accounting for demands
SUPPLY:Annual : +3%Jun – Oct: -10%Nov – May: +27%
DEMAND:Annual: +10%
Regulated Supply and In-Stream Flow Requirements at Key Locations Future
(2030)Historical (1977-2006)
Note: Supply is reported prior to accounting for demands
Watersheds Included in Study
Out-of-Stream Demand by Watershed
Conclusions and Future Directions
Changes in supply (average of all climate scenarios) 3% increase in annual flow at Bonneville However, 16% decrease in summer flow at Bonneville
Changes in demand (middle econ and climate scenarios) 10% increase in agricultural demand over basin 12% increase in agricultural demand over state
Some watersheds more impacted than others (see our poster on the Yakima River Basin)
Increased irrigation demand, coupled with decreased seasonal supply poses difficult water resources management questions, especially in the context of competing in stream and out of stream users of water supply.
Thinking towards the 2016 Forecast
Acknowledgements
Peer reviewers Alan Hamlet, Bob Mahler, Ari Michelson, Jeff Peterson
University of Washington Climate Impacts Group
Dana Pride WA Dep. of Ecology
THANK YOU!
SUPPLEMENTARY SLIDES
Yakima
Yakima Unregulated Supply
Yakima Demand
Yakima Unregulated Supply and Demand: Historical vs Future
Historical
Middle Climate Scenario
Yakima Future Supply and Demand: Unregulated vs Regulated Supply
Unregulated Supply
Regulated Supply
Yakima Curtailment and Unmet Demand
Historical (1977-2005) At least some curtailment of proratable
irrigation rights 45% of years (higher than observed)
Unmet Demand: 7,200 – 278,600 ac-ft per year; average of 108,000 ac-ft per year
Future (2030s) At least some curtailment of proratable
irrigation rights for 90% of years Unmet Demand: 14,300 – 434,000 ac-ft per
year; average of 154,000 ac-ft per year
Curtailment Uncertainties
1) monthly time step of model2) we are using a very simplified model and need something like the riverware model to capture all details3) USBR uses a "forecast" of supply which may be different from VIC supply4) demand does not match seasonally with entitlement expectations of USBR in managing the reservoir
Longer-Term Directions
2016 Report to State Legislature, improvements that are being considered Groundwater dynamics Columbia-basin scale economics (not just
state-level) Fuller inclusion of climate change scenarios More ground-truthing
Model Calibration/Evaluation Calibration:
Streamflows (we used calibration from Elsner et al. 2010 and Maurer et al. 2002)
Crop Yields (using USDA NASS values) Irrigation Rules (using reported irrigated extent
by watershed) Evaluation:
Streamflows (Elsner et al. 2010 and Maurer et al. 2002)
USBR Diversions from Bank’s Lake (for Columbia Basin Project) USBR Diversions: 2.7 MAF/yr (with conveyance losses) VIC-CropSyst: 2.5 MAF/yr (no conveyance losses) Results in a reasonable ~20% conveyance loss
Physical Systemof Damsand Reservoirs
Reservoir Operating Policies
Reservoir StorageRegulated StreamflowFlood ControlEnergy ProductionIrrigation ConsumptionStreamflow Augmentation
0100000200000300000400000500000600000700000800000900000
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
Flow
(cfs
)
VIC Streamflow Time Series
The Reservoir Model (ColSim) (Hamlet et al., 1999)
Slide courtesy of Alan Hamlet
ColSim Reservoir Model (Hamlet et al., 1999) for Columbia Mainstem
Model used as is, except for
Small reservoirs included for Yakima and Chelan
Withdrawals being based on VIC-CropSyst results
Curtailment decision is made part of the reservoir model
#*#*
#*#* #*#* #*
#* #*
#*#*#* #* #*#*
#*
#*
#*
#*
#*
Green triangles show the dam locations
Curtailment Rules (Washington State)Curtailment based on instream flow targets Columbia Mainstem Lower Snake Central Region (Methow, Okanogan, Wenatchee) Eastern Region (Walla Walla, Little Spokane,
Colville)
Prorated based on a calculation of Total Water Supply Available
Yakima
Yakima Reservoir Model
Irrigation demand from VIC/CropSystCurtailment rules
Proratable water rights prorated according to Total Water Supply Available (TWSA) calculated each month
Monthly Inflows
from VIC-CropSyst
Total System of Reservoirs (capacity 1MAF approx.)
Objectives:
• Reservoir refill by June 1st
• Flood space availability
Instream flow
targets
Gauge at Parker
T – TranspirationIP – Interception capacityI – InfiltrationIr – irrigationWd- Water demandQ – RunoffQ01 – Drainage from 0 to 1Q02 – Drainage from 0 to 2Qb – BaseflowW0 – water content in 0W1 – water content in 1W2 - water content in 2Tmin, Tmax – daily minimum and maximum temperatureWs – wind speedRH – Relative humiditySR – Solar radiation
Qb
Q12
T
IP
Redistribute I, W0, W1 and W2 to CropSyst layers
Q
Q01
W0,W1, W2
T0, T1, T2, IP, Wd
I
CropSyst
VIC
Ir
Daily Tmin, Tmax, Ws, RH, SR, I
VIC-CropSyst : Coupling Approach
Invoking CropSyst within VIC gridcell
Crop 1
VIC grid cell(resolution=1/16°)(~ 33 km2)
Crop 2
Non-Crop
Vegetation
CropSyst is
invoked
CropSyst is
invoked
http://www.hydro.washington.edu/2860/ Slide courtesy of Alan Hamlet
The UW CIG Supply Forecast
Application of the UW CIG Water Supply Forecast
WSU is building directly off of the UW water supply forecasting effort (Elsner et al. 2010) by starting with these tools that were developed by UW Climate Impacts Group: Implementation of the VIC hydrology model over the
Pacific Northwest at 1/16th degree resolution Reservoir Model, ColSim Historical climate data at 1/16th degree resolution Downscaled future climate data at 1/16th degree
resolution WSU added elements for handling agriculture:
integrated crop systems and hydrology irrigation withdrawals from reservoirs, and including some
smaller reservoirs, curtailment modeling economic modeling of farmer response
Uncertainties
1-Future climate (due to GCMs, greenhouse emission scenarios anddownscaling approach)
2-Model structure (VIC-CropSyst)
3-Water management and economic scenarios
4-Cropping pattern - discrepancy between multiple data sources
5-Irrigation supply – poor data on groundwater and surface waterproportions of the supply
6-Irrigation methods a)No information for upstream states b)Conveyance loss is not modeled (This is a proportion of the demand at each WRIA)
Walla Walla
Walla Walla Supply
Walla Walla Demand
Walla WallaSupply and Demand
Historical
Hadcm_B1
Example WRIA Results: – Supply in WENATCHEE
Example WRIA Results - Demand in WENATCHEE
Example WRIA Results – Supply and Demand in WENATCHEE