Can we expect food security, good nutrition and health in an increasingly water stressed world?
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Transcript of Can we expect food security, good nutrition and health in an increasingly water stressed world?
Ph
oto
: Dav
id B
razi
er/I
WM
I
www.iwmi.org
Water for a food-secure world
Can we Expect Food Security, Good
Nutrition and Health in an increasingly
Water Stressed World?
Colin Chartres and Pay Drechsel
www.iwmi.org
Water for a food-secure world
• This presentation will illustrate four key
areas which directly or indirectly support
Food Security, Nutrition and Human
health under Water Stress:
– Smart water allocation
– Well managed storage
– Safe wastewater reuse
– Increased water productivity.
www.iwmi.org
Water for a food-secure world
1. Smart water allocation between different
uses
1970s
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Water for a food-secure world
• Can We Expect Food Security, Good
Nutrition and Health in an Increasingly
Water-stressed World? Can WeCan We Expect Food Security, Good Nutrition and Health in an Increasingly Water-stressed World? Expect Food SecCan We Expect Food Security, Good Nutrition and Health in an Increasingly Water-stressed World?urity, Good Nutrition and Health in an Increasingly Water-stressed World?
Can We Expect Food Security, Good Nutrition and Health in an Increasingly Water-stressed World?
Can We Expect Food Security, Good Nutrition and Health in an Increasingly Water-stressed World?
2020
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Water for a food-secure world
How is allocation related to health? In dry environments:
• we have to capture and store as much water as is possible
• reuse as much as possible,
• allocate very smartly between different usages/users, and
• have a best crop per drop efficiency as each drop counts.
The critical point is that far too often water is managed sectorally,
with no national/regional policy that balances out needs and
risks
There is a water-energy-food- health-
environment nexus
www.iwmi.org
Water for a food-secure world
• Can We Expect Food Security, Good
Nutrition and Health in an Increasingly
Water-stressed World?
Can We Expect Food Security, Good Nutrition and Health in an Increasingly Water-stressed World?
Can We Expect Food Security, Good Nutrition and Health in an Increasingly Water-stressed World?
Example 2. The pros and cons of storage
• A key prevention measure to address water scarcity, and adapt to
climate change is Water Storage.
• Many IWMI & CPWF projects worked on improving storage from
institutional, hydrological and health perspectives.
• Storage is a very sensitive options closely related to a variety of
possible health challenges, which can, however, be mitigated.
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Water for a food-secure world
• Can We Expect Food Security,
Good Nutrition and Health in an
Increasingly Water-stressed
World?
Technology and Investment – investing in
water storage
4
43
74
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0
1,000 2,000
3,000
4,000
5,000 6,000
7,000
Ken
ya
Eth
iop
ia
Sou
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Afr
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Thai
lan
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Lao
s
Ch
ina
Bra
zil
Au
stra
lia
No
rth
Am
eri
ca
Low per capita storage (m3/capita)
World Bank (2003)
www.iwmi.org
Water for a food-secure world
Water storage • Focus on water for agriculture, incl. livestock;
• Integrated into most water systems
• Save water over time for access at critical periods
• Diverted from rivers, rainwater harvesting, aquifers
• High variety
– Tanks, reservoirs
– Groundwater
– Large / small
– Open / closed
– Man-made / natural
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Water for a food-secure world
Health risks of open water
• Risk of drowning,
• Water quality issues,
• Vector-borne diseases, like increased malaria
transmission associated with:
– Small reservoirs
– Surface irrigation (estates & small-scale)
– Rainwater harvesting ponds
– Livestock watering
www.iwmi.org
Water for a food-secure world
Case Ethiopia
Koka reservoir in a relatively low- risk malaria zone
(Source: MoH & WHO 2007)
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Water for a food-secure world
Koka
• Reservoir crucial for livestock watering
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Water for a food-secure world
y = -27.51ln(x) + 62.462R² = 0.9149
0
20
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120
0 1 2 3 4 5 6 7 8 9
Mala
ria c
ases/1
000 p
eo
ple
Distance f rom the reservoir (km)
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ay-0
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ay-0
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ay-0
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un-0
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un-0
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Wate
r le
vel chang
e (
m)
Mala
ria c
ases/1
000 p
eo
ple
Observed Predicted Water level change
Koka • Malaria cases correlate
with
– Distance from reservoirs
– Water level fluctuations
(Source: Kibret et al. 2009)
Mala
ria c
ases/1
000 p
eople
Wa
ter
leve
l ch
an
ge
(m
)
(Source: Lautze 2008)
www.iwmi.org
Water for a food-secure world
0.00
2.00
4.00
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8.00
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12.00
Aug-0
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7Mean n
o.
mosquitoes p
er
trap p
er
nig
ht
An. arabiensis (Reservoir villages)
An. pharoensis (Reservoir villages)
An. arabiensis (Control villages)
An. pharoensis (Control village)
0.00
2.00
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6.00
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7Mean n
o.
mosquitoes p
er
trap p
er
nig
ht
An. arabiensis (Reservoir villages)
An. pharoensis (Reservoir villages)
An. arabiensis (Control villages)
An. pharoensis (Control village)
Micro-scale analysis
• Adult Anopheles more abundant closer to reservoir
• More breeding sites near shore line, mainly in livestock hoof prints
(Source: Lautze 2008)
www.iwmi.org
Water for a food-secure world
Malaria at Koka Lake, Rift Valley • Increased transmission near lake related to water management
• Research result: Decision support for dam operation based on larval control via water level fluctuation is possible and grazing access needs to be controlled
• However, nothing was done because the government decided that the need for electricity was paramount
• Subsequent analysis has shown that there would be minimal impact on power generation by implementation of a water management regime to reduce malaria risk
www.iwmi.org
Water for a food-secure world
Malaria Risk mapping at basin and national
scale
no cases reported
1 - 5
6 - 50
51 - 100
101 - 200
201- 500
>500
Tanks/rivers
Major roads
Malaria cases
per 1000 inhabitants
Example
Sri Lanka
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Water for a food-secure world
Annual cost of malaria control
per individual protected
US$
Insecticide spraying 2.75
Impregnated bed nets 1.02
Larviciding 0.53
Water management 0.26
Konradsen et al. (1999)
Bulletin of the World Health Organization, 77: 301-309
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Water for a food-secure world
Wastewater generation
Farm worker Traders Kitchen staff Consumer
Wastewat treatment
Safe Irrigation Praices
Hygienic Handling Practices
Safe food washing and preparation
Awareness creation to create
demand for safe produce
Non- or post-treatment options for health risk reduction
1989 WHO Guidelines Example 3: The need for water reuse
Key question: How to reuse wastewater safely where there are no sewers and treatment plants e.g. due to water scarcity?
Research is focusing on:
• Actual risk assessment and
• Low-cost risk mitigation sing the multiple barrier approach where conventional treatment is lacking
www.iwmi.org
Water for a food-secure world
Wastewater generation
Farm worker Traders Kitchen staff Consumer
Wastewater treatment
Safe Irrigation Practices
Hygienic Handling Practices
Safe food washing and preparation
Awareness creation to create
demand for safe produce
Non- or post-treatment options for health risk reduction
Irrigation water
quality thresholds
Wastewater generation
Wastewater treatment
Farm worker Traders Kitchen staff Consumer
1989 WHO Guidelines WHO-FAO-UNEP (2006)
Health-based
targets
0
5
10
15
20
25
30
35
Nu
mb
er
of
Tre
atm
en
t P
lan
ts
Region
Business (e.g., hotel,airport)
Hospital
Military
School
Municipal/Township
Community-level
Wastewater and faecal sludge treatment
plants in Ghana
Operational Status
How many of them work ?
Source: Murray & Drechsel, 2011
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Water for a food-secure world
• Drip and furrow irrigation • Sedimentation ponds • Cessation of irrigation • Filter • Limited soil splash • Improved water fetching • Increased retention time • On-farm treatment ponds
Farm based options for risk
reduction
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Water for a food-secure world
• Supporting die-off • Display w/o recontamination • Safe washing & refreshing • Safe cutting practices, etc.
Market based
options
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Water for a food-secure world
Effective & safe vegetable washing
Street
food
sector
based
options
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Water for a food-secure world
Research is informed by field work across Asia and Africa
Ouagadougou
IWMI Offices 2010 Water Quality, Heath & Environment Other IWMI projects
www.iwmi.org
Water for a food-secure world
Research produced many options for health risk reduction
which supported efforts by WHO and FAO and fed into
international guidelines
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Water for a food-secure world
Source: IWMI, 2009
Risk assessment in
Ghana’s 5 biggest cities:
Daily risk is with
2,500- 3,000 farmers and traders of exotic vegetables 20,000-26,000 staff of street food restaurants, 600,000- 800,000 street food consumers
12,000 lost DALYs*/year
*DALYs: Disability Adjusted Life Years
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Water for a food-secure world
Hazard comparison for Accra, Ghana, via different exposure pathways
Flooding of main river passing city
Swimming at Accra's beaches
94 $/DALY
>500 $/DALY Children exposed to open drains
Failure of WWTP
Faecal sludge disposal exposure
Workers exposed at WWTPs
Contaminated drinking water pipes
Wastewater irrigated vegetables
*DALYs: Disability Adjusted Life Years , *WWTP: Waste Water Treatment Plant Sources: Labite et al., 2010; IWMI, 2009
Cost-effectiveness of interventions:
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Water for a food-secure world
Example 4. Increasing Water Productivity
In terms of health and water productivity there are two key challenges: • Feeding over 2 billion more people a nutritious diet • Dealing with overeating and waste
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Water for a food-secure world
Food for Thought
• Based on a 2500 cal/day diet water demand under
business as usual will increase to approximately 13,000
km3 by 2050 1
• Growing GDP is encouraging the increased consumption
of animal proteins, which require more water to produce
• Wastage of food due to on-farm losses and in the
supply/consumption chain is unacceptably high
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Water for a food-secure world
• 5
Nutritional intake in India
→ Share of calorie supply from grain will decrease
→ More than half the calorie supply will be from non-grain products by 2050
← Per capita calorie from food
grains is declining in the 1990’s
← Vegetables and animal products
consumption is increasing
Changing consumption patterns
1541 1454 1542 1653 15871521
1401
419 451 479 566706
9121083
114 107 125 161 195 341 477
0%
25%
50%
75%
100%
1961 1971 1981 1991 2001 2025 2050
Sh
are
of
ca
lori
e s
up
ply Animal
products
Non-grain
crops
Food grains
Source: 1961-2001 data from FAOSTAT
Changing consumption patterns
1541 1454 1542 1653 1587 1521 1401
419 451 479566 706 912 1083114 107
125161 195
341477
0
500
1000
1500
2000
2500
3000
3500
1961 1971 1981 1991 2001 2025 2050
Calo
rie s
up
ply
Animal
products
Non-grain
crops
Food grains
Source: 1961-2001 data from FAOSTAT , IWMI RR 119
, IWMI RR 119
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Water for a food-secure world
How do we increase productivity?
• Doubling crop and water productivity in poorly performing systems in 20 years via:
– Coordinating supply and demand in water delivery in
irrigation
– Improving conjunctive use of surface and groundwater to minimize salinization
– Consider supplementary irrigation options in rainfed systems
– Improving fertilizer management
– Reforming governance and institutions
– Empowering farmers
– Developing multiple use water systems
– Ensuring access to finance and markets
www.iwmi.org
Water for a food-secure world
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3Figure 4: Standardised Gross Value of Production per unit water consumed by ETcrop
* surface water and public wells ** private wells
Productivity of Water at 40 Irrigation Systems:
There is ample scope for improvement.
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Water for a food-secure world
• Reduce waste and excessive consumption
Food waste, EU27: 179 kg/cap, year (2010)
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Water for a food-secure world
So can we expect food security, good nutrition
and health in a water stressed world
Yes if we:
• carefully balance the need for food production with other domestic
and ecosystem water demands
• reduce water loss through harvesting, storage and recycling
• increase water productivity in food production.
Harmonizing agricultural production with the
environment and learning to understand the
value of ecosystem services will be the
biggest challenge
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Water for a food-secure world
But this means:
• Throwing out business as usual approaches
• Focusing on better water governance and institutions to improve allocation processes
• Harmonizing agriculture and water management using basin/landscape approaches to support vital ecosystem services
• Proactively managing water to limit disease risks
• Recycling and reusing waste water and nutrients
• Reducing over consumption and food waste