This document discusses challenges related to global water scarcity and food security given projected population growth. It notes that dramatic population growth is projected for water-scarce areas of South Asia and Africa. Current agricultural practices rely heavily on irrigation, which buffers rainfall variability but is unsustainable. Solutions proposed include optimizing crop planting locations, improving irrigation efficiency, developing water pricing and storage strategies, and increasing rainfed crop yields through technology and management practices. The overall framing questions whether global food demands in 2050 can be met sustainably given water and land constraints.

1. Naresh Devineni, City University of New York and NOAA-CREST
Upmanu Lall, Columbia University and Columbia Water Center
2/2/2015
1

2. >2 Billion of the projected 8.5 billion in S. Asia
for the 2050 projection, but highest % growth in
Africa
(25% of world population 4% of area)
Can dramatic population growth really take
place in water scarce areas?
Would food transfers be essential?
WWAP 2012
Water Scarcity
& Potential
Future
Demands

3. Can we feed 9 billion
people in 2050?
=
Do we have the water to
grow food and provide
energy and minerals for
9 billion?
Yield
Plateaus
Increasing
Irrigation
Irrigation
buffers
rainfall
variability

4. Least
Investment/Poorest
Average crop yield of irrigated cereals = 442 Mg/km2
Average yield of rainfed cereals = 266 Mg km2 Siebert and Doll,
P.:doi:10.1016/j.jhydrol.2009.07.0
Rice
~40% global irrigation
water
~30x energy use where
groundwater used
Potential for 30%+ savings

5. Average income levels
& irrigation in India
The highest
concentrations of
irrigation
% OF AREA UNDER
IRRIGATION
FAO AQUASTAT 2007 MAP
India as an example: 1950 to 2000
Food production: 4.2x (population
2.75x)
Irrigation buffers rainfall variability
Lessons from
both analytical
and field work
in India:
Solutions for a
highly water
stressed setting

6. • High uncertainty in climate models as to future precipitation change, with poor
representation of variability.
• Precipitation is highly variable and reliance on irrigation will continue to increase.
• Increasing water stress generally unless a variety of demand management measures
are adopted.
• Innovation towards agricultural sustainability in countries such as
India and China, that have large populations relative to their water, energy and
arable land endowment, and yet have opportunity for improvement in productivity
metrics such as crop yield per unit water or energy use, can show us the way to
achieve global water-food-energy sustainability.
• Integrated scenarios considering specific water infrastructure investments
and conservation measures are explored -- values of these are estimated
from shadow price analysis.

7. Water Stress considering climate
variability, renewable supply and
current use
Central Govt
Food
Security Goal
Fixed Price
Rice-Wheat
Procurement
Variable Monsoon
Climate
Irrigation
needed
Ineffective
Canal system
106 new wells
added/year
State gives free
electricity
Flood irrigation
when electricity
available
Low water
efficiency
Groundwater
decline
Electricity
Unreliable
Pump Burnout
Need Deeper Well
Poverty Worse water & energy access for all
Anatomy of the Crisis
10

8. River Linking/Storage
Water/Energy Credits/Pricing
Groundwater Recharge
Canal Controls – Assure Supply
Crop Procurement System
Optimization
Subsidy Structure & Regulation
Including Irrigation Technologies
Climate, Market, Hydrologic, Crop Monitoring and Forecasting Systems
Active Risk Management, & Extension Delivery
On-Farm Activities
Irrigation Technology/Practices
Tillage
Soil Moisture and Nitrogen Sensors
Crop Choice
Rainwater Harvesting/Recharge
Impacts on Water and Energy Availability for all other uses
Reducing Post Production food loss

9. Did the green revolution stick
in the wrong places?
Could India’s water stress be reduced
simply by changing where what is grown?
Where? How much? Climate role?
National Scale

10. Cropi
Procurement Price
Climate Scenario
>100 years of daily precip
& temp, Districtj
Unit Cost of Cultivation
for Cropi in Districtj
Cropi Eligible
for Districtj ?
Seasont Cropi
water deficit
Districtj
Cropi Av. yield
Districtj
Max Irrigation
water available
Districtj Seasont
Area for
Cropi in
Districtj
Av. Cropi
Production
Districtj
Net National
Ag. Revenue
Total Crop Area
Districtj
Total Irrigated
Area Districtj
National Cropi
Procurement
National
Nutrition
Needs
National
Nutrientk
Production
Simulation-Optimization Model
• National Goals : Max Expected Net Revenue
• Meet Food Goals; Constrain Irrigation & crop area
• Space-time resolution: District, Daily
Unit Irrigation Cost
Districtj
National Scale:
How could we change the procurement strategy?

11. • Highest yield
• Contributes bulk of grain to
national procurement system
• Rapid Groundwater Depletion
Punjab:
Rice water application ~ 2m/season
Rain ~0.65 to 0.8 m/year

12. Rice
Pulses
Other Cereals
Oilseeds
Legend
India_State_UT_Boundary_ver1
India_State_UT_Boundary_ver1
Rice_optim
<
-0.75
-0.75
--0.50
-0.5
--0.25-0.25
-0.00.0
-0.25
0.25
-0.50
0.50
-0.75
>
0.75
PPP Opportunity
An even bigger story if
corporate and
government
participation was used
to address market
price risk and
technology innovation
in the agricultural
supply chain

13. Current
Practice
Optimum pattern
under rainfed
Optimum pattern
under irrigated
National Agricultural Revenue
($ billions)
8.58 17.75 22.14
Irrigation Water Requirement
(1000 billion liters)
165 - 132
Energy usage (GWH) 14856 - 14759
Analysis in support of national food procurement system reform17

14. Legend
districts_2001
max_sd_optim
0 - 0.3
0.3 - 0.6
0.6 - 1
1 - 2
2 - 5
India_State_UT_Boundary_ver1
Legend
districts_
max_sd_optim
0 - 0.3
0.3 - 0.6
0.6 - 1
1 - 2
2 - 5
India_State
Normalized Water deficit / Mean
Annual Rainfall for existing cropping
patterns
Normalized Water deficit/ Mean
Annual Rainfall with crop
diversification
Analysis in support of national food procurement system reform18

15. 2/2/2015
19
Green
Revolution

16. • Optimize where what is grown to meet nutrition and income goals
(global, national)
• Address access, income, climate, water source, storage, distribution
• Supply chain development for price and technology support
• Economic signals (national)
• Incentives, subsidies, enforcement of pricing and metering
• Dynamic pricing for crops (procurement system and exports/imports) and for water/energy
inputs to adapt to climate and market forecasts
• Coordinated food and water storage management
• On farm technologies and support (extension)
• Efficiency improvements in irrigation monitoring and application. Target 30% on-farm water
efficiency from current 10-15%
• Rainfed crop productivity increases through on-farm water storage and soil moisture
management
• Risk Management (across scales)
• Food vs Water vs Financial Storage Development and Trade/Aid
• Improving Yields of dryland crops; Brackish water tolerance

17. • The current global water scarcity crisis is marked by two major factors
• poor water use strategies that derive from unregulated and poorly priced use and
climate variability.
• The projections for the future do not effectively address these issues, or the
possible ways by which the trajectory could evolve
• Better water use strategies can “buy” us almost as much water as the
projected population increase
• if per capita use does not change, then this may be an effective approach as part of a
larger strategy
• Water stress may increase = Poverty trap and poor productivity. Linking
income, food, water smoothing strategies is important for an effective
transition
• Technological innovation is a necessity and there are many options.