Economic Analysis of the 2014 California Drought on Agriculture. Post-Assessment
and Prospects for 2015
Josué Medellín-Azuara
Nadya Alexander, Richard E. Howitt,
Duncan MacEwan and Jay R. Lund
California Water and Environmental Modeling Forum
March 10, 2015
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Water and People in California
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Source: Hanak et al. (2011): Managing California Water from Conflict to Reconciliation
California depends on an engineered statewide network
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Source: Hanak et al. (2011): Managing California Water from Conflict to Reconciliation
Agriculture in California
• $45 B in annual value ($35 M crops)
• 300+ commodities
• 9 M acres (7M in Central Valley)
• 400,000 Jobs
• Largest in value and size in US
• More than 30 MAF/yr. in applied water (75-80% of statewide beneficial use)
• Trend towards permanent crops 4 Source NASS CDL 2011
California’s highly engineered water supply system is loosing its long-term ability to cope with drought as permanent crops water demand increases and groundwater overdraft continues
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SWAP Model
• More than 90% of the irrigated agriculture
• Positive mathematical programming
• 20 Crop groups
• Maximizes net returns to land and management
• SWAP and C2VSim linked to IMPLAN
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C2VSIM SWAP
(Agricultural Production)
IMPLAN
(Region -Wide Effects)
Changes in • Employment • Total Sector
Output • Value-Added
Changes in • Revenues • Cropping patterns • Inputs Land,
water, supplies
Water supply scenarios Surface cutbacks Groundwater R.S. Fallowing update
Changes in agricultural revenues
INPUTS
MODEL
OUTPUT
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Changes in • Pumping
capacity • Groundwater
table depths
Water Shortage and Changes in Groundwater
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Region Surface Water
Shortage
Additional Groundwater
Use (MAF/yr)
Additional Groundwater
Cost ($ Million/yr)
Sacramento Valley 1.8 0.9 35.4
San Joaquin Valley 1.8 1.5 71.9
Tulare Lake Basin 3.0 2.6 340.3
Central Valley Subtotal 6.5 5.0 447.6
Other Areas 0.1 0.1 6.3
Statewide Total 6.6 5.1 6.3
2014 Estimated Irrigated Area Reductions
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2014 Estimated Gross Revenue Reduction
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2014 Estimated Drought Impacts
Drought impact Loss Quantity Water supply impacts, 2014 drought
Surface water reduction 6.6 million acre-feet
Groundwater pumping increase 5 million acre-feet
Net water shortage 1.6 million acre-feet
Statewide agricultural impacts, 2014 drought
Crop revenue loss $810 million
Additional pumping cost $454 million
Livestock and dairy revenue loss $203 million
Total direct losses 1.5 billion
Total economic cost $2.2 billion
Total job losses 17,100
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Hydro-economic models are useful for improving quantitative understanding of a water system assessing economic costs, and screening water management alternatives
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UC Davis estimate Idle Land
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Evapotranspiration Estimation Methods
• Crop coefficients and reference evapotranspiration
• Energy balance methods like SEBAL and METRIC
Net Surface Radiation
Sensible Heat Flux
Latent Heat Flux
Soil Heat Flux
Instantaneous Vegetation Indices
Raster Image
Daily Evapotranspiration
Raster Image
Daily Crop Coefficient
Raster Image
Local CIMIS Station Weather
Data
Digital Elevation
Maps
RefET Evapotranspiration
Calculations
Land Use and Crop Type Maps
Landsat Spectral and
Thermal Image
METRIC Model
Surface Energy Balance
Landsat Spectral and Thermal Image Land Use
NDVI Evapotranspiration (mm)
CIMIS stations with METRIC 20-km and 30-km radii
These radii are considered optimal for processing in relatively uniform areas.
0
50000
100000
150000
200000
250000
300000
350000
400000
3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0
Freq
uen
cy
Daily Crop ET (mm/day)
Actual Crop ET Values for the Sacramento - San Joaquin Bay Delta July 24, 2014
Lodi West
Twitchell
Remote sensing for estimating idle land and consumptive use can improve hydro-economic model calibration.
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Can we do better?
Lund et al. (2014). Why California Needs More GrouManagement http://californiawaterblog.com/2014/05/26/why-californias-agriculture-needs-groundwater-management/
Prospects for 2015
• Reduced groundwater tables
• The role of water markets • East San Joaquin Valley and other dry places
• Southern California
• Remote sensing information might receive more attention
• Recalibration of hydro-economic models
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Concluding remarks
• Drought total impacts are in the order of $2.2 billion and 17,100 jobs.
• Idle land estimates 430 thousand acres with SWAP, remote sensing-based 470-500 thousand acres
• Remote sensing useful to improve model’s representation of the system
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Acknowledgments
• Forest Melton from NASA for sharing idle land estimates
• Department of Water Resources for connection with the C2VSIM model. Tariq Kadir, E. Can Dogrul, Charles Brush
• Thomas Harter, Giorgos Kourakos for additional groundwater information
• Andy Bell, and Alyssa Obester, Alvar Escriva-Bou for GIS, remote sensing assistance and research support
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Further information Drought Report Website: https://watershed.ucdavis.edu/2014-drought-report http://californiawaterblog.com/
Josué Medellín [email protected]
