The document discusses solutions for addressing global water scarcity. It identifies four key solutions: 1) 'smart' irrigation technologies like drip irrigation and precision surface irrigation, 2) wastewater reuse, 3) improved groundwater governance, and 4) helping agriculture mitigate and adapt to climate change through practices like Alternate Wetting and Drying. It notes that while drip irrigation can increase yields, other low-cost solutions may be more suitable depending on local context. Overall, it argues that a variety of decentralized, adaptable, and inexpensive 'smart water solutions' will be needed to manage increasing water variability under climate change.

1. Identifying solutions
for a water-stressed
world
Alain Vidal
ICID2015, Montpellier, October 2015

2. Challenges for today and tomorrow
Source: OECD

3. Global water scarcity

4. Climate variability will impact
on food production
Source: Socioeconomic Data and
Applications Center (SEDAC)
• Crop yields drop
by 2050 under
BAU
 Maize 16%
 Rice 21%
 Wheat 42%

5. The water crisis : a global risk to business
Source: Global Risks Perception
Survey 2014.
World Economic Forum, Global
Risks 2015 - Insight Report

6. Identifying solutions for a water-stressed world
1. ‘Smart’ irrigation
2. Waste water reuse
3. Groundwater governance
4. Help agriculture become
part of climate solutions
Photo: Hamish John Appleby/IWMI

7. Incentives to rapid expansion of drip irrigation…
Yet suitability depends on context
Photo: Hamish John Appelby / IWMI

8. Bring smart and affordable ICT to everyday
farm management for smallholders
• Mobile-phone and web-
based agro-advisory
system developed and
tested in Sudan, Ethiopia
and Egypt
• Spatial data translated
into simple SMSs - both
qualitative and
quantitative, and both
on-demand and
weekly “push”

9. Precision surface irrigation
A viable alternative to drip irrigation
Pakistan: Land and Water
productivity increases,
reduced diesel costs
Photos: Arif Anwar / IWMI

10. 0
5
10
15
20
25
30
Diluted
wastewater
or polluted
water
Untreated
wastewater
Groundwater Treated
wastewater
River Other
surface
water bodies
Rainfed Irrigation
canal
Open
drainage
Numberofcities
In and around three of four cities in
the developing world, farmers use
polluted irrigation water for the
production of high-value crops
Global survey - irrigation source in urban
& peri-urban areas

11. Photo: Pay Drechsel/IWMI
Wastewater: a valuable asset

12. Growth of irrigation in India driven by
groundwater
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
Irrigatedareain1000ha
Canal irrigated area Tank irrigated area Groundwater irrigated area
Canal
Tanks
Source: Mukherji et al. 2013.

13. India: Twin cases of ‘over-abstraction’ and
‘under-utilization’
Source: IWMI

14. Solar pumps – renewable, but sustainable?
Getting the incentives right
Infographic: Rachel Cramer / IWMI

15. Help agriculture become
part of the climate solutions
“Business as usual” (BAU)
agriculture emissions
would comprise ~50% of
allowable emissions to
achieve a 2°C world
Gt CO2e per year
9 11
40
74
2010 2050
(Business as usual)
2050
(2°C target)
Non-agricultural
emissions
Agricultural and
agriculture-driven
land-use change
emissions
~50%
49
85
22

16. Alternate-Wetting-and-Drying
(AWD)
30% water
20-50% GHG
Without compromising
yield
• Keep flooded
for 1st 15 days
and at flowering
• Irrigate when
water drops to
15 cm below the
surface
0
2
4
6
8
10
12
14
16 15.0
8.7
-42%
0
2
4
6
8
10
12
14
16
tCO2-eq/ha*season
4.9
3.9
-20%
0
2
4
6
8
10
12
14
16
0
2
4
6
8
10
12
14
16
-22%-28%
6.0
4.7
6.4
4.6
Hilly mid-slopes Delta low-lying
Summer-
Autumn
Winter-
Spring
Sander et al. in press IRRI
AWDConventional

17. EAST AFRICA Irrigation – unexplored opportunity
 Increase, stabilize,
diversify
production
 Climate
resilience
 60%
increase in
soil carbon*
*temperate system
Entry et al. 2002
Major policy initiative in
African Nations
Led
by:

18. Smart water solutions
Because of increased
variability, a continuum of
water management
technical and institutional
innovations are needed
 decentralized, adaptable,
inexpensive
 applicable under scenarios
of increasing or decreasing
rainfall