Quantifying the Role of Agricultural Groundwater

Use for Drought Mitigation

Sasha Richey, Muhammad Barik, Begum Rushi, Keyvan Malek

Washington State University

Background to CRB

• 4th largest river in the U.S.; 259,500 mi2

• Over 37,000 MW of installed hydro capacity

• 1909 Boundary Waters Treaty Columbia River Treaty (1964) = increased hydro and flood control

BACKGROUND

Background to CRB

BACKGROUND

2013 Crop Value: ~$1bil

78.7% U.S.

2013 Crop Value: ~$2.9bil

2015 economic lossesWheat: $212.5milApples: $86.52mil

WSDA, 2015 Publication No. [AGR PUB 104-495]

Groundwater in the CRB

Columbia Plateau Regional

Aquifer System

• 44,000 mi2

• Overlying sedimentary deposits, underlying CRBG

• 26% irrigation water use from CPRAS in 1985-2007 (1.4 MAF of 5.3 MAF total) [Vaccaro et al., 2015]

BACKGROUND Vaccaro et al., 2015, USGS PP 1817

History of Drought

BACKGROUND

Goal and Methods

What tools can we use to quantify the role of groundwater in the CRB?

Does the role of groundwater change during drought?

Goal and Methods

What tools can we use to quantify the role of groundwater in the CRB?

Does the role of groundwater change during drought?

• VIC-CropSyst

• GRACE

• Reports

• Additional Studies

• Emergency well authorizations

Water Balance Equations

𝑑𝑆

𝑑𝑡= 𝑃 − 𝐸𝑇 − 𝑄

𝑑𝑆

𝑑𝑡=𝑑𝑆𝑊

𝑑𝑡+𝑑𝑆𝑀

𝑑𝑡+𝑑𝑆𝑊𝐸

𝑑𝑡+𝑑𝐺𝑊

𝑑𝑡

METHODS

Water Balance Equations

𝑑𝑆

𝑑𝑡= 𝑃 − 𝐸𝑇 − 𝑄

𝑑𝑆

𝑑𝑡=𝑑𝑆𝑊

𝑑𝑡+𝑑𝑆𝑀

𝑑𝑡+𝑑𝑆𝑊𝐸

𝑑𝑡+𝑑𝐺𝑊

𝑑𝑡

METHODS

GRACE ColSIM,Yak-RiverWare

VIC-CropSyst VIC-CropSyst Unknown

ColSIM,Yak-RiverWareVIC-CropSystVIC-CropSyst

Model Overview: VIC-CropSyst

METHODS

VIC: HydrologyLiang et al, 1994 and Elsner et al, 2010

CropSyst:Cropping Systems

Stockle and Nelson 1994

Crop TypesBlueberry Seed_SodGrass Peaches SugarBeetSeed Peas

Cranberry Alfalfa Pear SwissChardSeed PeaGreen

Strawberries AlfalfaOrGrassHay Walnuts BeanSeed Peppers

Caneberry CloverHay OthTreeFruits MustardSeed Potatoes

Barley GrassHay OthTreeNuts CilantroSeed Rhubarb

Buckwheat Sorghum OrchardUnknown FescueSeed Squash

Corn Sudangrass AlfalfaSeed GrassSeed Sugarbeets

CornUnknown Timothy BeetSeed Asparagus Radish

Oats Herbs BluegrassSeed DryBeans Dill

Rye OtherCrops BromegrassSeed BeanGreen Canola

Triticale Hops BrusselsSproutsSeed Broccoli Mustard

SpgWheat Watermelon CarrotSeed Cabbage Camelina

WinWheat Mint CornSeed Carrots RapeSeed

DurWheat Pasture OnionSeed Cauliflower Safflower

OthSmallGrains NLCDPasture_Hay PeaSeed Chickpea GrapeJuice

Sunflowers OtherHays PotatoSeed SweetCorn Grapes

CerealGrainUnknown Pasture_Grass RadishSeed Cucumber

BulbTulip Apples RyegrassSeed Garlic

BulbDaffodil CherryOrchard SafflowerSeed Lentils

CloverWildflowers NectarineOrPeach SpinachSeed Onions

Model Overview: VIC-CropSyst

METHODS Adam et al., 2014; Liu et al., 2014

ColSim [Hamlet & Lettenmaier, 1999] and Yakima-RiverWare provide reservoir dynamics and streamflow

Water Balance Equations

𝑑𝑆

𝑑𝑡= 𝑃 − 𝐸𝑇 − 𝑄

𝑑𝑆

𝑑𝑡=𝑑𝑆𝑊

𝑑𝑡+𝑑𝑆𝑀

𝑑𝑡+𝑑𝑆𝑊𝐸

𝑑𝑡+𝑑𝐺𝑊

𝑑𝑡

METHODS

Water Balance Equations

𝑑𝑆

𝑑𝑡= 𝑃 − 𝐸𝑇 − 𝑄

𝑑𝑆

𝑑𝑡=𝑑𝑆𝑊

𝑑𝑡+𝑑𝑆𝑀

𝑑𝑡+𝑑𝑆𝑊𝐸

𝑑𝑡+𝑑𝐺𝑊

𝑑𝑡

METHODS

GRACE ColSIM,Yak-RiverWare

VIC-CropSyst VIC-CropSyst Unknown

ColSIM,Yak-RiverWareVIC-CropSystVIC-CropSyst

GRACE in the CRB

METHODS

ΔGW

ΔSM

Modeled Water Balance Components: CRB

RESULTS

𝑑𝐺𝑊

𝑑𝑡=𝑑𝑆

𝑑𝑡− (

𝑑𝑆𝑊

𝑑𝑡+𝑑𝑆𝑀

𝑑𝑡+𝑑𝑆𝑊𝐸

𝑑𝑡)

GRACE ColSIM,YakRW

VIC-CropSyst

VIC-CropSyst

RESULTS

𝑑𝐺𝑊

𝑑𝑡=𝑑𝑆

𝑑𝑡− (

𝑑𝑆𝑊

𝑑𝑡+𝑑𝑆𝑀

𝑑𝑡+𝑑𝑆𝑊𝐸

𝑑𝑡)

GRACE ColSIM,YakRW

VIC-CropSyst

VIC-CropSyst

Modeled Water Balance Components: CPRAS

Solving for GW

RESULTS

𝑑𝐺𝑊

𝑑𝑡=𝑑𝑆

𝑑𝑡− (

𝑑𝑆𝑊

𝑑𝑡+𝑑𝑆𝑀

𝑑𝑡+𝑑𝑆𝑊𝐸

𝑑𝑡)

GRACE ColSIM,YakRW

VIC-CropSyst

VIC-CropSyst

Modeled Irrigation Demand

RESULTS

dGW/dt and Irrigation Demand

RESULTS

WA Forecast-Draft GW Report

RESULTS

• Majority of GW use is from the CPRAS

• Highlighted regions have long term declines• Largest in Southwest Flank

of the Rattlesnake Hills in the Yakima Valley and in the Odessa Subarea

• Integrated groundwater assessment will be included in the next Forecast (2021)

WA Emergency Well Authorizations

• 2001: 34437.10245 AF

• 2005: 332.1238 AF

• 2015 (1/3): 1511.284 AF

RESULTS

Summary

• GRACE and VIC-CropSystgenerally match on dS/dt

• dGW/dt needs to be ground truthed over consistent region

• Modeled irrigation demand magnitude is small

• Reported emergency drought well magnitude is very small… supplemental rights?

• Investigate role of water transfers, on-farm storage ponds, etc. on total signal

• Not a clear consensus on the role of groundwater in CRB or drought… yet! • But not as significant as in CA

[crop]details_URL=http://en.wikipedia.org/wiki/Barleydescription=Barley (Hordeum vulgare)canopy_growth=canopy_coverharvested_part=grainC_species=C3life_cycle=annualstem_type=herbaceous[emergence]model=thermal_time[growth]TUE_equation=TUE_curveTUE_scaling_coef=0.6 (Note, in V.B. version this is entered as negative value)TUE_scaling_coef_veg=0.6 (Note, in V.B. version this is entered as negative value)TUE_at_1pKa_VPD=4.8TUE_at_1pKa_VPD_veg=4.8RUE_PAR=2.8RUE_basis=photosynthetically_active_radiationLWP_reduces_canopy_expansion=-1000LWP_stops_canopy_expansion=-1300early_growth_limit_temp=8[transpiration]ET_crop_coef=1.14

max_water_uptake=13.0000000000 Maximum water uptakestomatal_closure_leaf_water_pot=-1300wilt_leaf_water_pot=-2000[canopy_cover]initial_cover=0.05maximum_cover=0.8mature_green_cover=0.3mature_total_cover=0.7[phenology]maturity_significant=trueemergence=24flowering=630peak_LAI=600filling=680maturity=1115senescence=720tuber_init=resolution=daybase_temp=3cutoff_temp=25maximum_temp=25[root]root_sensitivity_water_stress=0.2max_root_depth=1.5root_length_at_emergence=12 //cm root_depth_emerge - sow_depthsow_depth= 0.08

root_density_distribution_curvature=0.00001[morphology]max_canopy_height=1[inactive_period]consider_inactive_days=7 at end or restart of growth activityinducement_temperature=5.0minimum_duration=[season]start_DOY_WA=105start_DOY_ID=105start_DOY_OR=105duration_WA=100duration_OR=100duration_ID=100[harvest]unstressed=0.45translocation_max=0.35[CO2]growth_ratio_elevated_to_baseline_ppm=1.2elevated_reference_conc=600baseline_reference_conc=360

Reservoir Modeling