Science and Research Needs Issues associated with the Future of Water for Food

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• Science and Research Needs Issues associated with
  the Future of Water for Food

Dr. Richard G. Allen, University of Idaho
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Science and Policy Issues

• What tools are needed to better manage water?
• What are the challenges for Food Security?

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Water Supply

• In developing countries micro supplies
• Improve the physical access and timing to the
  supply
• Example Treadle Pumps
• International Development Enterprises IDE / FAO
  / IPTRID / World Bank / Gates Foundation
• Shallow GW (lt 8 m)
• Small Investment 20 - 100
• Human Powered
• Increase Crop Intensity (via a dependable
  supply)

(avoid bureaucracies)
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Water Supply

• Macro supplies
• More Surface Reservoirs
• advantages
• local food security
• more effective utilization of inputs and water
• reduce slash and burn agriculture by
  concentrating agriculture in river bottoms
  (George Hargreaves, USU, 1992)
• Spatial distribution of water and population
• disadvantages
• inundation of land, ecosystems, displacement of
  people
• large costs
• Better use of Aquifers
• Offset disadvantages of Surface Reservoirs
• Larger storage supply available during drought
  (if wells in place)
• Require Power Consumption

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Water Productivity

• Are we close to genetic limits on increasing
• Kg of biomass per Kg of water consumed?crop
  water productivity for wheat, rice, and maize has
  not changed appreciably in twenty-five years.
  (Zwart and Bastiaanssen 2004, Agricultural Water
  Management)
• Harvestable index?Since about 1980, only minor
  increases in the harvest index have been
  achieved it appears unlikely that further major
  yield increases in cereals can result from
  further major increases in HI. (Sinclair and
  Gardner, 1998 Principles of Ecology in Plant
  Production )

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Irrigation Systems

• Developed countries
• Reduce evaporation
• Increase the transpiration fraction(more
  harvested kg / kg water consumed)
• Achieve full ground cover more quickly
• higher plant density / quicker growth
• Reduce environmental impacts

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Off-Season Evaporation
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Off-Season Evaporation
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Irrigation Systems

• Developing countries
• Put dependable, cheap systems in the hands of
  small farmers
• Help convert from subsistence to cash crops
• Small Scale Irrigation Systems
• Produced Locally
• Drip using buckets or small tanks for supply
  (IDE, IWMI)
• Mini sprinkler systems (IDE design by Jack
  Keller)

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Science Issue

• Its time for better Water Accounting
• Increasing productivity in irrigated
  agriculture constraints and physical realities
  Dr. Chris Perry, World Bank consultant in
  review by Agric. Water Management
• Its time we all Study and Adhere to the
  Hydrology of Basins

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Hydrologic Realities

• Its Not the Efficiency, Stupidfor
  example,Water conservation in irrigation can
  increase water use. Ward and Pulido-Velazquez.
  2008. Proceedings of the National Academy of
  Sciences

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Hydrologic Cycle
slide courtesy MNR, Ontario, Canada
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Fundamental Precepts

The law of Conservation of Mass Matter can not
be created nor destroyed All liquid water (not
evaporated) can not be created nor destroyed.
Thus all nonevaporated components must be
"somewhere" and must reappear "somewhere."
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Irrigation Hydrology

• Basic Hydrologic Truths
• 99 of the earth is underlain by groundwater
  (Freeze and Cherry, Groundwater 1979)
• Deep percolation "losses" are not "lost" to the
  hydrologic system
• 1. Losses seep downward vertically to
  groundwater.
• 2. Groundwater moves laterally and discharges
  to a surface water source.

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Return and Reuse of Diversions

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Sound Advice

• If you want to know how much water can be
  saved and used elsewhere in a basin, go to
  where the River meets the Ocean. The flow there
  is what you have to work with.
• Dr. Lyman S. Willardson, Utah State Univ. 1982
• Rivers under Tension
• --Nile Indus Ganges Jordan Yellow
• --Colorado Rio Grande Platte Republican
  Arkansas

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Water Accounting

• http//www.citg.tudelft.nl/live/pagina.jsp?ida821
  743d-99c4-47e6-a06f-1051f8e342fflangen

http//www.citg.tudelft.nl/live/pagina.jsp?ida821
743d-99c4-47e6-a06f-1051f8e342fflangen
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Water Accounting
The River Basin Perspective
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On the Horizon

• Water Accounting From Satellites
• -- First steps towards a standardized description
  of water resources
• by Wim Bastiaanssen
• at WaterAccounting.com

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Examples

• Yemen

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Yemen hydrologic incongruencies

• Groundwater is being mined at such a rate that
  parts of the rural economy could disappear within
  a generation. Christopher Ward, Principal
  Operations Officer for the Middle East and North
  Africa,World Bank, 2001
• Most farmers will benefit from investment in
  water conservation and irrigation efficiency
• the increase in water prices will encourage
  farmers to adopt water-efficient technologies,
  which will help to relieve pressure on
  groundwater.

Comment Increased efficiency will do a better
job of evapotranspiring water. It will likely
have a negative impact on GW
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Yemen hydrologic incongruencies

• GW recharge comes from surface water excesses
  (rainfall or excess irrigation)
• Groundwater resources are vital for Yemens
  agriculture. For their recharge they depend
  mainly on spates running water and rainfall.
  Qahtan Yehya A.M. Al-Asbahi, National Integrated
  Water Resources Management Program, Yemen
• There are also estimates that there will be an
  improvement for using the available water at a
  35 to 60 higher efficiency rate in irrigated
  areas, which will result in a reduction of water
  consumption. (wrong)
• (Improved uniformity will increase ET) (Dr. Chris
  Perry, World Bank Consultant)

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Yemen hydrologic incongruencies

• RememberWater conservation in irrigation can
  increase water use. Ward and Pulido-Velazquez.
  2008. Proceedings of the National Academy of
  Sciences (Study of effects of subsidizing
  farmers along the Rio Grande of N.Mexico to
  increase efficiencies.River flows went down.)

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Upper Snake River Basin --Idaho Eastern Snake
Plain Aquifer Comprehensive Aquifer Management
Plan
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Water flow from Snake River to Aquifer and from
Aquifer to River
Tributary underflow

Snake River Plain Aquifer
Snake River
Recharge P Diversionsriver
Inflowtrib.underflow ET Surface Returns
Yellow dots are irrigation wells
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Island Park
American Falls Reservoir
Thousand Springs
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Excess snowmelt runoff divert via low
efficiencies
enhanced aquifer discharge to River builds back
late summer flows
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The economy supported by crops produced in the
Upper Snake River Basin, including that produced
by Ground-water have an estimated value of 10
billion annually
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Comprehensive Aquifer Management Plan
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Twin Falls, Idaho Times-News March 25, 2009 (at
magicvalley.com)
The CAMP plan - ordered by the Legislature two
years ago because of a declining aquifer and
rising number of water lawsuits - is estimated to
cost 70 million to 100 million during its first
10 years to pay for recharge, ground-to-surface
water conversions and other projects.One
amendment requires that CAMP "recognizes that
incidental ground water recharge occurs as a
result of the exercise of surface diversions,"
and that the implementation plan should include
measures that "recognize the benefits of
incidental recharge."This amendment came from
groups in eastern Idaho who don't feel the plan
provides enough credit for water that filters
into the ground during normal agricultural
operations, otherwise known as incidental
recharge.
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• Use Fractions rather than Efficiencies

Allen et al., 1994 Molden et al. 1996
Willardson et al. 1996 Perry et al. 2008
Quantity Diverted (initial diversion)
(to replace irrigation efficiency term)
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(to replace irrigation efficiency term)

• Consumed Fraction

CF
(to ocean)
Is a 40 CF bad ? Is a 40 Irrigation
Efficiency bad?
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• Reusable Fraction

-
-
RF
RF 1 CF NRF 1 - RF
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• Examples

Snake River EF 0.40 (Irrigation Efficiencies
are Low) RF 0.60 Therefore CF 0.40 (60
returns for
reuse downstream)
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Future Need Better Quantification

• of Supplies
• tighter GW surveys, water balances and models
• of Consumption
• satellite-based Evapotranspiration mapping

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Satellite-based ET Mapping

• SEBAL Bastiaanssen, WaterWatch
• applied world-wide
• ET and crop productivity
• METRIC
• Univ. Idaho / Idaho Dept. Water Resources
• Univ. Nebraska / DNR
• New Mexico Tech.
• Montana DNRC
• Nevada DRI / NOSE
• Colorado NCWCD / Riverside Tech.
• World Bank - Morocco

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August 19, 2005 Scottsbluff, NE area False
Color, top ET, bottom
Collaborative work with Dr. Ayse Irmak, UNL
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Evapotranspiration from METRIC/Landsat -- mm
per year
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METRIC in Idaho Water Management
Mapping ET at high Resolution with Internalized
Calibration

• Left -- water-right polygons outlined in black
  are superimposed on an aerial photograph. Right
  -- same polygons layered over an image of
  seasonal evapotranspiration (Geospatial
  Solutions Magazine -- gismap.geospatial-solutions.
  com)

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Performance of Irrigation Projects
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Irrigation Project Performance
Twin Falls Canal Company, Idaho
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METRIC

• Idaho Department of Water Resources program,
  Mapping Evapotranspiration from Satellites,
• -- Top 16 finalist in the 2009 Innovations in
  American Government Awards competition of
• Harvard University - Kennedy School - Ash
  Institute for Democratic Governance and
  Innovation

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Crop consumptive use in rice (ETact)
   
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Rice yield - Iran
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Water productivity rice (Yield/ET)
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Climate Change Impacts

• Higher ET demands
• Longer Growing Seasons
• Changes in Seasonal distribution of Precipitation
• Earlier Snowmelt / More Liquid Precip.
• If increased temperature causes drier air, then
  Water Productivity (Kg/Kg) may reduce (unless
  counterbalanced by CO2 enrichment)