1. CALIFORNIA’S WATER WAR: PART II Balancing Agricultural and Domestic Water Demands Sharon Liu Urban Planning M206A – Intro to GIS March 19, 2012

2. INTRODUCTION THE FACTS California has a significant agriculture industry. California has a growing population. OUR PROBLEM Both crops and people need water. Freshwater is a finite resource. THE FUTURE Who gets the water when both demands increase? How will this impact California’s agriculture industry? 2 SOURCES: Global ENSO SST Index (University of Washington) YEAR 2000 moderate La Niña (dry weather)

3. CROP VALUE: STATES 3 SKILLS: graduated symbols, aggregating attribute fields (Crop Value = Field/Misc. Crops + Fruits/Nuts + Commercial Vegetables) SOURCES: UCLA Mapshare State and Country Boundaries, US Department of Agriculture (2000 Crop Values), 2000 US Census Bureau

4. CROP VALUE: US VS. CA 4 in billions SKILLS: EXCEL pie charts SOURCES: US Department of Agriculture (2000 Crop Values) 1)~17% of US total crop value 2)>50% of US crop value for both commercial vegetables and fruits and nuts

5. POPULATION PROJECTIONS 5 SKILLS: EXCEL bar chart, inset map, graduated symbols, creating indices (fractional population change) SOURCES: UCLA Mapshare County, State, and Country Boundaries; California Department of Finance (2000 population & decadal projections)

6. EVALUATION METRICS Agricultural Water Demands Domestic Water Demands Irrigation Efficiency (proxied by evapotranspiration) SCALES Spatial: county Temporal:monthly, annual, decadal SIMPLIFYING ASSUMPTIONS Water conservation efforts were not considered. Climate variability (and climate change) were not considered. – Total available water is fixed. Other water uses (industrial, thermoelectric, mining, etc) assumed constant. Freshwater sources and transport (via aqueducts) were not considered. 6

7. DOMESTIC WATER 7

8. PER CAPITA WATER USE 8 SKILLS: graduated symbols, creating indices (pcwu = public supply withdrawals / total population), attribute subset selection (top 20% counties) SOURCES: UCLA Mapshare County, State, and Country Boundaries, California Department of Water Resources (2000 Irrigated Crop Acres and Water Use, 20x2020 Water Conservation Plan), US Geological Survey (2000 Estimated Water Use) 2010 State Water Conservation Goal: 20% Reduction by 2020

9. IRRIGATION EFFICIENCY Evapotranspiration 9

10. RECALL: WHAT IS EVAPOTRANSPIRATION? ET = Evaporation + (Plant) Transpiration Sufficient H 2 0  ↑ crop growth (↑ ET) = ↑ crop value($) Where does the H 2 0 come from? – Native (rainfall, groundwater, etc) – Irrigation (imported water) 10

11. WEATHER STATIONS 224 stations total 94 stations with data for year 2000 Use CIMIS data to calculate ET (Currently, 141 active and 83 inactive) 11 SKILLS: inset map, original data (CIMIS station locations) SOURCES: UCLA Mapshare County, State, and Country Boundaries, California Department of Water Resources (2000 Irrigated Crop Acres and Water Use), California Irrigation Management and Information System (station locations and period of record)

12. MONTHLY EVAPOTRANSPIRATION 12 WINTER SPRING

13. MONTHLY EVAPOTRANSPIRATION SUMMER FALL 13

14. STATISTICAL SIGNIFICANCE 14 SPATIAL AUTOCORRELATION z-score = 9.41: >99% likelihood that pattern is NOT random Moran’s Index = 0.323: values have some correlation SKILLS: graduated symbols, hot spot analysis, aggregating attribute fields (annual = ∑monthly), model (kriging and clip), analysis (kriging), spatial statistics (spatial autocorrelation [Moran’s Index]) SOURCES: UCLA Mapshare County, State, and Country Boundaries; California Irrigation Management and Information System (locations and annual ETo)

15. MODELED EVAPOTRANSPIRATION 15 SKILLS: creating indices (AW Efficiency = ETAW/AW), aggregating attribute fields (Applied Water = ΣAW for all 20 crop types), graduated symbols SOURCES: UCLA Mapshare County, State, and Country Boundaries, California Department of Water Resources (2000 Irrigated Crop Acres and Water Use)

16. SIGNIFICANT CROP TYPES 16 SKILLS: graduated symbols SOURCES: UCLA Mapshare County, State, and Country Boundaries, California Department of Water Resources (2000 Irrigated Crop Acres and Water Use) California is the #1 Alfalfa Producer in the US!California’s #1 Crop ($18.6 million in 2000)

17. FUTURE IMPACTS Water Volume and Total Crop Production Value 17

18. WATER VOLUME: COUNTY 18 SOURCES: UCLA Mapshare County, State, and Country Boundaries; California Department of Water Resources (2000 Irrigated Crop Acres and Water Use) * Linear projections based on % change in population in each county

19. WATER VOLUME: STATE AGRICULTURAL WATER: Variable In 2000, 30,497 Mgal/day yielded $15.5 billion. In 2050, 79,040 Mgal/day could potentially yield $40.1 billion. DOMESTIC WATER: Minimum Required MAX AVAILABLE WATER: Fixed 36,904 Mgal/day WHICH CROPS GET WATER? 25,049 Mgal/day is available for agriculture. 19 25,049 $?? deficit (53,991) ($??)

20. PLANNING SCENARIOS Scenario I: Maximize crop production by first watering crops with the highest irrigation efficiency Scenario II: Maximize crop profit by first watering crops with the greatest crop value Scenario III:Maintain crop diversity by applying a proportional reduction in agricultural water Scenario IV: Specialize crops (focus on commercial vegetables and fruits & nuts) by first watering crops with the highest irrigation efficiency 20 AgriculturalDomestic Field and Misc. Commercial Vegetables Fruits and NutsSelf-SuppliedPublic Supply HOW TO BALANCE THE WATER DEMANDS?

21. EX. SCENARIO III: MAINTAIN CROP DIVERSITY Scenario III: Maintain crop diversity by applying a proportional reduction in agricultural water __________________________________ WHICH CROPS GET WATER? 25,049 Mgal/day is available for agriculture. Between 2000 and 2050, total crop production value would decrease by $2.4 billion. 21 25,049 $13.1 deficit (53,991) ($27.0)

22. SUMMARY Freshwater is a finite resource (future demand >> supply). There are many different approaches on how to allocate the water available for agriculture. – Irrigation Efficiency (using ET) is a statistically significant, yet complicated option. (It also depends on modeled ETAW values.) Results suggest that there will be a decrease in $$ generated from the agriculture industry. 22

23. MODEL 23 SKILLS: model creation (Kriging interpolation of annual precipitation and clipping to California boundary) SOURCES: UCLA Mapshare County, State, and Country Boundaries; California Department of Water Resources (2000 Irrigated Crop Acres and Water Use) Can also be applied to monthly ETo data in California.

24. SKILLS Model Measurement/Analysis Original Data Inset Map Graduated symbols Aggregating attribute fields Creating indices Attribute subset selection Distance Charts, images Hotspot Analysis (Spatial Analyst) Spatial Statistics Time-based Analysis 24

25. Questions? 25