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

1. Science and Research Needs Issues associated with the Future of Water for Food Dr. Richard G. Allen, University of Idaho The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

2. Science and Policy Issues • What tools are needed to better manage water? • What are the challenges for Food Security? The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

3. 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 (< 8 m) • Small Investment $20 - $100 • Human Powered • Increase Crop Intensity (via a dependable supply) (avoid bureaucracies) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

4. 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 The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

5. 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) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

6. 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 The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

7. Off-Season Evaporation The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

8. Off-Season Evaporation The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

9. 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) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

10. Science Issue • It’s 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 • It’s time we all Study and Adhere to the Hydrology of Basins The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

11. Hydrologic Realities • It’s Not the Efficiency, Stupid…for example,“Water conservation in irrigation can increase water use.” Ward and Pulido-Velazquez. 2008. Proceedings of the National Academy of Sciences The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

12. Hydrologic Cycle slide courtesy MNR, Ontario, Canada The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

13. 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." The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

14. 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. The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

15. The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

16. Diversion Returns Upper River Middle Lower ocean Irrigation Projects or Cities Return and Reuse of Diversions The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

17. 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 The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

18. The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

19. Water Accounting • http://www.citg.tudelft.nl/live/pagina.jsp?id=a821743d-99c4-47e6-a06f-1051f8e342ff&lang=en http://www.citg.tudelft.nl/live/pagina.jsp?id=a821743d-99c4-47e6-a06f-1051f8e342ff&lang=en The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

20. Water Accounting The River Basin Perspective The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

21. On the Horizon Water Accounting From Satellites -- First steps towards a standardized description of water resources by Wim Bastiaanssen at WaterAccounting.com The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

22. Examples • Yemen The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

23. 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 The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

24. Yemen – hydrologic incongruencies • GW recharge comes from surface water excesses (rainfall or excess irrigation) • “Groundwater resources are vital for Yemen’s 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) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

25. Yemen – hydrologic incongruencies • Remember:“Water 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.) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

26. Upper Snake River Basin --Idaho Eastern Snake Plain Aquifer – Comprehensive Aquifer Management Plan The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

27. 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 Utah State University Seminar, 23 March, 2009

28. Eastern Snake River Plain Aquifer – interactions with the Snake River Spring Discharge Aquifer Water Level Months Island Park American Falls Reservoir Thousand Springs

29. Excess snowmelt runoff – divert via low ‘efficiencies’ enhanced aquifer discharge to River builds back late summer flows The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

30. The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

31. “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” The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

32. Comprehensive Aquifer Management Plan The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

33. 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. The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

34. Q EF = ET Q Div Q = Quantity Evaporated(changed to vapor) ET Q Div Allen et al., 1994; Molden et al. 1996; Willardson et al. 1996; Perry et al. 2008 Use ‘Fractions’ rather than Efficiencies = Quantity Diverted(initial diversion) (to replace ‘irrigation efficiency’ term) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

35. Q Q ET NR Q Div Q = Quantity not reusable (besides ET) NR (to replace ‘irrigation efficiency’ term) Consumed Fraction + CF = (to ocean) Is a 40% CF “bad” ? Is a 40% Irrigation Efficiency “bad”? The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

36. Q Q ET NR Q Q Div Div Reusable Fraction - - RF = RF = 1 – CF NRF = 1 - RF The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

37. Examples Snake River: EF ~ 0.40 (Irrigation Efficiencies are Low) RF ~ 0.60 Therefore: CF ~ 0.40(60 % returns for reuse downstream) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

38. Future Need: Better Quantification • of Supplies • tighter GW surveys, water balances and models • of Consumption • satellite-based Evapotranspiration mapping The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

39. 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 The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

40. August 19, 2005 Scottsbluff, NE area False Color, top ET, bottom Collaborative work with Dr. Ayse Irmak, UNL The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

41. Evapotranspiration from METRIC/Landsat -- mm per year The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

42. “Mapping ET at high Resolution with Internalized Calibration” METRIC in Idaho Water Management 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) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

43. “Performance” of Irrigation Projects

44. Irrigation Project Performance Twin Falls Canal Company, Idaho

45. 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 The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture

46. actual evapotranspiration computed with SEBAL model – Gilan (Iran) Crop consumptive use in rice (ETact)

47. SEBAL model – Gilan (Iran) Rice yield - Iran

48. SEBAL model – Gilan (Iran) Water productivity rice (Yield/ET)

49. 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) The Future of Water for Food -- A discussion of the critical issues and challenges in the use of water for agriculture