For Want of Food: Groundwater and Agricultureag-groundwater.org/files/56589.pdf · Ground-Water...
Transcript of For Want of Food: Groundwater and Agricultureag-groundwater.org/files/56589.pdf · Ground-Water...
Imag
e: A
dam
Har
t-D
avis
, 200
6
For Want of Food:For Want of Food:Groundwater and Groundwater and
AgricultureAgriculture
Thomas HarterThomas HarterUniversity of California, DavisUniversity of California, Davis
[email protected]@ucdavis.eduhttp://groundwater.ucdavis.eduhttp://groundwater.ucdavis.edu
http://aghttp://ag--groundwater.orggroundwater.org
Thomas Harter, University of California, Davis, 2010
OutlineOutline
Global water and groundwater useRole of groundwater in agriculture, especially global food productionCurrent and future challenges to groundwater in ag/rural areas
Thomas Harter, University of California, Davis, 2010
Timm Sauer et al., WRR, 10 June 2010:
“The complex interdependencies between water
resources and food production …. an evolving global
food crisis”
Thomas Harter, University of California, Davis, 2010
Total Water Use MapTotal Water Use Map
LargestWater Users
IndiaChina
United StatesPakistanJapan
ThailandIndonesia
BangladeshMexico
Russian Federation
modified from:United Nations World Water Development Report, 2009
LargestGroundwater Users
(80% of global)IndiaChina
United StatesIran
BangladeshPakistan
100 km3
= 80 MAF
CA:
4,000 km3
3,200 MAF+6,400 km3
+5,100 MAFfrom rain
to ag
Global Use:
55
Thomas Harter, University of California, Davis, 2010
Groundwater Connection to Food: USE OF GROUNDWATERGroundwater Connection to Food: USE OF GROUNDWATER
modified from: United Nations World Water Development Report, 2009
Asia: 30%US: 42%CA: 30%-60%
Thomas Harter, University of California, Davis, 2010
Water UseWater Use
46%
Groundwater Irrigated Area Data are from: Shah, Villholth, Burke, “Groundwater: a global assessment of scale and significance”, IWMI, 2007
53%
50%
16%
20%
And % Share of Groundwater-Irrigated Area
(km3)
Thomas Harter, University of California, Davis, 2010
Trends inTrends inGroundwater UseGroundwater Use
from: United Nations World Water Development Report, 2009
MAF
200
160
120
80
40
240km3
from: Shah et al, 2007
CA: 13-25 km3/ 10-20 MAF
Thomas Harter, University of California, Davis, 2010
Groundwater for IrrigationGroundwater for Irrigation
UN World Water Development Report II, 2006
Shah, Villholth, Burke, “Groundwater: a global assessment of scale and significance”, IWMI, 2007
Total irrigated area:1,200 Mac/480 Mha
GW irrigated area:320 Mac/130 Mha
IWMI, 2007
Thomas Harter, University of California, Davis, 2010http://www.psychohistorian.org/img/adnd/world-building/climate/koppen-map.jpg
Climate Type and GW Use CentersClimate Type and GW Use Centers
Thomas Harter, University of California, Davis, 2010
Groundwater RechargeGroundwater Recharge& Major GW Use in Agriculture& Major GW Use in Agriculture
from: United Nations World Water Development Report, 2009; Shah, Villholth, and Burke, 2007
• Total precip on land: 100,000 km3 (90,000 MAF)• Evaporative returns: 67% of precip• Renewable supply: 29,000 km3 (23,000 MAF)• Total applied water use: 4,000 km3 (3,200 MAF)
=>Irrigated ag applied water: 2,800 km3 (2,200 MAF)
• Irrigated ag ET: 1,550 km3 from AW, 650 km3 from rain
• Groundwater in ag: ~1,000 km3 (800 MAF)• Total rainfed ag water use: 6,400 km3 (5,100 MAF)• Total groundwater recharge: 2,200 km3 (1,800 MAF)
Thomas Harter, University of California, Davis, 2010
Global Fraction of CroplandGlobal Fraction of CroplandRelative to GW Pumping Centers, 1992Relative to GW Pumping Centers, 1992
Ramankutty N and Foley JA (1999) Estimating historical changes in global land cover: Croplands from 1700 to 1992. Global Biogeochemical Cycles, 13, 997-1027.
majorgroundwater
users
CA:•14% of US crop, 7.5% of US livestock•$100 billion economic value•$36 billion farm cash receipts•81,500 farms and ranches•400 commodities•nearly half of U.S.-grown fruits, nuts and vegetables
Thomas Harter, University of California, Davis, 2010
Population Map of the WorldPopulation Map of the World& Major GW Withdrawal Centers& Major GW Withdrawal Centers
Modified with world population map from: Nature 439, 800 (16 February 2006) | doi:10.1038/439800a
Thomas Harter, University of California, Davis, 2010
World PopulationWorld Population
IPCC, Fourth Assessment Report, 2007, Workgroup III
UN, World Population Growth to 1700-2300, 2004
10
15
Thomas Harter, University of California, Davis, 2010
2020thth Largest Countries by PopulationLargest Countries by Population
UN
, Wor
ld P
opul
atio
n G
row
th to
170
0-23
00, 2
004
Thomas Harter, University of California, Davis, 2010from: IWMI, Comp Assess. Water Mgmt in Ag, 2007
Per Capita Meat Consumption
Per Capita Grain Demand (driven by feed)
Thomas Harter, University of California, Davis, 2010
from
: IW
MI,
Com
p As
sess
. Wat
er M
gmt i
n A
g, 2
007
Water Use
Land Use
2050
20
50
Thomas Harter, University of California, Davis, 2010
Challenges to Meeting the Groundwater NeedsChallenges to Meeting the Groundwater Needsfor Global Food Securityfor Global Food Security
Groundwater Storage LossGroundwater Storage Loss18 km3/yr
450,000 km2 area0.3m/yr water level decline
1.7 km3/yr (1.3MAF/yr) 1962-2003 (satellite & USGS Model)
110,000 km2 areaLarge annual fluctuationsDuring drought: up to 6m/yr water level decline
10 km3/yr (0.8 MAF/yr)450,000 km2 areaAverage decline: 0.1m/yrsome areas: few m/yr decline
M Rodell et al. Nature 460, 999-1002 (2009) doi:10.1038/nature08238
GRACE averaging function.
M Rodell and Famiglietti, J. Hydrol 263:245-256
INDIA
HIGH PLAINS AQUIFER, USA
Thomas Harter, University of California, Davis, 2010
Additional Groundwater Demands: Additional Groundwater Demands: BiofuelsBiofuels
Global: 10% of energy from biomass (4/5 from wood, dung, crop reGlobal: 10% of energy from biomass (4/5 from wood, dung, crop residue)sidue)Global: 5% of biomass production for liquid fuel => 2% of transpGlobal: 5% of biomass production for liquid fuel => 2% of transport ort energy;energy;BiofuelsBiofuels: Brazil (54% of all sugar cane) and U.S. (23% of all corn) => 7: Brazil (54% of all sugar cane) and U.S. (23% of all corn) => 77% 7% of global market in 2007of global market in 2007Only sugar cane has better GHG footprint than fossil fuelsOnly sugar cane has better GHG footprint than fossil fuelsTotal irrigation water use for Total irrigation water use for biofuelsbiofuels::
Currently 44 kmCurrently 44 km3 3 (35 MAF), 3% in U.S., 2% in China(35 MAF), 3% in U.S., 2% in China225 km225 km3 3 (180 MAF) after implementation of current national policies (an(180 MAF) after implementation of current national policies (and 30M d 30M ha (75M acres) additional ha (75M acres) additional landuselanduse))
from: United Nations World Water Development Report, 2009
Thomas Harter, University of California, Davis, 2010
Water and EnergyWater and Energy
from: United Nations World Water Development Report, 2009Thomas Harter, University of California, Davis, 2010
Climate Change:Climate Change:Change in GW RechargeChange in GW Recharge
Salt water intrusion Salt water intrusion (coastal areas)(coastal areas)Changes in ETChanges in ETChange in Change in ““safe safe yield:yield:””
Less recharge from Less recharge from streams in arid and streams in arid and semisemi--arid regionsarid regionsChange in diffuse Change in diffuse recharge from recharge from precipprecip
More extreme More extreme events, including events, including droughts => more droughts => more reliance on reliance on groundwater groundwater (savings account)(savings account)
From: Döll and Flörke, 2005In: IPCC 4th Assessment Report; http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch3s3-4-2.html
Thomas Harter, University of California, Davis, 2010
Groundwater Connection to Food: IMPACTGroundwater Connection to Food: IMPACT1. Groundwater Salinization1. Groundwater Salinization
Example: Eastern San Joaquin ValleyExample: Eastern San Joaquin Valley
EC-F
ield
[uS/
cm]
UplandMerced
ModestoTurlock
0
500
1000
1500
2000
2500
3000
UplandMerced
ModestoTurlock
Mean Mean±SE Mean±SD
Original GAMA data from Table 1 and 4 in:
Landon and Belitz, 2008. Ground-Water Quality Data in the Central Eastside San Joaquin Basin 2006: Results from the California GAMA Program, USGS Data Series 325.
57 Public Supply Wells(USGS – GAMA)
20 Flowpath &Monitor Wells
Non-Dairy Ag Landuse(USGS – GAMA)49 Hilmar Domestic Wells
(1986, 2001 – no trend)
4 ModestoDairy
Domestic Wells(2008)
Thomas Harter, University of California, Davis, 2010
Groundwater Connection to Food: IMPACTGroundwater Connection to Food: IMPACT2. Nitrate in Groundwater2. Nitrate in Groundwater
UN World Water Development Report II, 2006
Note: 10 mg N/l = 10 kg N/km2/yr for each 1 mm/yr recharge
Thomas Harter, University of California, Davis, 2010
N Balance in Three Corn SystemsN Balance in Three Corn SystemsKenya Kenya –– North China North China –– Midwest USMidwest US
Vitousek et al., Science, 2009
Thomas Harter, University of California, Davis, 2010
Groundwater Loading fromGroundwater Loading fromAnimal Agriculture with Manure Reuse in Intense Feed CropsAnimal Agriculture with Manure Reuse in Intense Feed Crops
Thomas Harter, University of California, Davis, 2010
Impact 1950Impact 1950--2007:2007:Nitrate in California Domestic/Municipal WellsNitrate in California Domestic/Municipal Wells
Thomas Harter, University of California, Davis, 2010
Future Impacts Likely Increase:Future Impacts Likely Increase:Delay of Impact due to GW AgeDelay of Impact due to GW Age
Age at 100 ft (30 m) depth
Age at 300 ft (100 m) depth
Harter et al., 2009
Thomas Harter, University of California, Davis, 2010
Ways out of a Global Food CrisisWays out of a Global Food Crisis
Improvements in water storage (reservoirs, Improvements in water storage (reservoirs, groundwater banking) and delivery efficiencygroundwater banking) and delivery efficiencyImprovements in Improvements in agag water productivity through water productivity through new breeding / genetically modified cropsnew breeding / genetically modified crops
Drought and salt (!!) toleranceDrought and salt (!!) toleranceHigher yieldHigher yield
Desalination (brackish water, seawater, water Desalination (brackish water, seawater, water reuse in farming and urban areas)reuse in farming and urban areas)Liberate water as a free market commodity & Liberate water as a free market commodity & include externalities / supply & demandinclude externalities / supply & demand
Thomas Harter, University of California, Davis, 2010
Future Challenges toFuture Challenges toFood Supply & WaterFood Supply & Water
Around the GlobeAround the Globe
Decelerating agricultural productivity growth (ultimately due toDecelerating agricultural productivity growth (ultimately due tobiophysical limits [biophysical limits [Beadle and Long, 1985Beadle and Long, 1985; ; BugbeeBugbee and Salisbury, and Salisbury, 19881988])])Physical limits to crop land expansion (current reserves mostly Physical limits to crop land expansion (current reserves mostly in in Africa, Africa, S.AmericaS.America))Conflicting demands to Conflicting demands to landuselanduse & water use [& water use [BouwerBouwer, 2000, 2000; ; RosegrantRosegrant et al., 2002et al., 2002, Hightower & Pierce, 2008], Hightower & Pierce, 2008]
Urban vs. industrial vs. agricultural vs. energyUrban vs. industrial vs. agricultural vs. energyWithin Within agag: Food vs. feed vs. fiber vs. (: Food vs. feed vs. fiber vs. (bio)fuelbio)fuel
Declining soil quality (e.g., tropical soils) [Declining soil quality (e.g., tropical soils) [Foley et al., 2005Foley et al., 2005; ; RamankuttyRamankutty et al., 2002et al., 2002]]Constrains to Constrains to agag intensification due to environmental and human intensification due to environmental and human health regulations [health regulations [RockstroemRockstroem et al., 2004et al., 2004; ; TilmanTilman et al., 2001et al., 2001; ; Van Van HofwegenHofwegen, 2006, 2006].].
=> nitrate, pesticides, salts, pharmaceuticals, pathogen => nitrate, pesticides, salts, pharmaceuticals, pathogen contamination of groundwatercontamination of groundwater
Climate change => agricultural productivity changeClimate change => agricultural productivity change
Thomas Harter, University of California, Davis, 2010
Groundwater Resources:Groundwater Resources:Challenges around the GlobeChallenges around the Globe
Overdraft in most productive Overdraft in most productive agag regions (e.g., CA, High Plains, regions (e.g., CA, High Plains, NW India, North China Plain)NW India, North China Plain)Increased food, feed & Increased food, feed & biofuelbiofuel demands => expanded water demands => expanded water useuseIncreased pumping cost (due to overdraft)Increased pumping cost (due to overdraft)Energy requirements (e.g., India)Energy requirements (e.g., India)Compromise to future water security in fossil Compromise to future water security in fossil gwgw use areas use areas (Middle East/North Africa)(Middle East/North Africa)Degradation of groundwaterDegradation of groundwater
SalinizationSalinizationNutrients, pesticidesNutrients, pesticidesEmerging contaminants?Emerging contaminants?
Impact to wetlands, streams, downstream usersImpact to wetlands, streams, downstream usersCompetition with urban water users, environmental water Competition with urban water users, environmental water needsneeds
Modified from: Shah, Villholth, Burke, “Groundwater: a global assessment of scale and significance”, IWMI, 2007 Thomas Harter, University of California, Davis, 2010
IMPACT USE
Groundwater
SurfaceWater
NaturalResources
Urban/Domestic/IndustrialActivities
EcosystemsEnergySector
AgricultureClimate Change
Thomas Harter, University of California, Davis, 2010
IMPACT USE
Groundwater
SurfaceWater
NaturalResources
Urban/Domestic/IndustrialActivities
EcosystemsEnergySector
AgricultureClimate Change
Ag-Groundwater-Climate Change
Salinity
Nutrients/Nitrogen
Animal Ag => Pathogens/Pharmaceuticals
Livelihood
EnvironmentalJustice
GW Use & Quality @Ag-Urban-Ecosystem Interface
GW & Global Food Security
Ag-Groundwater-Energy Nexus
Thomas Harter, University of California, Davis, 2010
Toward Sustainable GW Use?Toward Sustainable GW Use?
Controlled increase in Controlled increase in gwgw use in Latin America and Subuse in Latin America and Sub--Saharan Africa to Saharan Africa to improve rural livelihoodimprove rural livelihoodImplement effective direct/indirect means to regulate Implement effective direct/indirect means to regulate gwgw withdrawalswithdrawals
supplysupply--side managementside managementArtificial recharge, aquifer recovery, rainwater harvestingArtificial recharge, aquifer recovery, rainwater harvestingWastewater reuseWastewater reuseConjunctive use, groundwater banking, integrated water managemenConjunctive use, groundwater banking, integrated water managementtInterbasinInterbasin transferstransfers
demanddemand--side managementside managementPricing (energy, water)Pricing (energy, water)Legal and regulatory controlLegal and regulatory controlWaterWater--rights/permitsrights/permitsIncentivesIncentives
GW Demand ManagementGW Demand ManagementIrrigation efficiency increaseIrrigation efficiency increaseDrought & salt tolerant crops (reuse!)Drought & salt tolerant crops (reuse!)Breeding of crops with higher water productivityBreeding of crops with higher water productivityCrop diversification: more cash per dropCrop diversification: more cash per dropOccupational diversificationOccupational diversification
Improve data base / data collection / monitoringImprove data base / data collection / monitoringBetter understanding of Better understanding of gwgw supply and demandsupply and demandPublic educationPublic education
Modified from: Shah, Villholth, Burke, “Groundwater: a global assessment of scale and significance”, IWMI, 2007
Thomas Harter, University of California, Davis, 2010
Resource evaluationResource evaluationAgricultural Agricultural management practicesmanagement practicesHazard assessmentHazard assessmentPollution controlPollution controlPollution assessmentPollution assessment
GeochemistryGeochemistryMicrobiologyMicrobiologyTransport / Physics Transport / Physics & Geology& GeologyMonitoringMonitoring
Water rightsWater rightsDischarge Discharge regulationsregulationsLanduseLanduseplanningplanningEconomic Economic incentivesincentivesLocal/regional Local/regional planning and planning and managementmanagementStakeholder Stakeholder interestsinterestsPoliciesPolicies
GROUNDWATER
QuantityQuality
AGRICULTURE,Ecosystems,
& Urban/Industry/EnergyLanduse Systems:
Demand (Quantity)Usability (Quality)
IMPACT USE
Technical Measures
Institutional Measures
Education
StakeholderParticipation
Imag
e: A
dam
Har
t-D
avis
, 200
6
…how obligate exactly…
…how facultative exactly…
Homo sapiens –Obligate or Facultative groundwater species?