WATER AND FOOD

Charles R. O’Melia

Johns Hopkins University

omelia@jhu.edu

After Alexander Zehnder

Sustainability as the Driver of Innovation

Alexander J.B. Zehnder

Challenges in the Water Area

Waterborne disease, with emphasis on developing countries

Water for agricultureWater infrastructurePesticides, hormonally active agents,

pharmaceuticals, etc.Water and ecosystems

Water availability and cereal import comparison between 1980–84 and 1995–99

0 1000 2000 3000 4000 5000-100

010

020

030

040

050

060

0

Water [m3/cap/yr]

Net

cer

eal i

mpo

rt [

kg/c

ap/y

r]

Afghanistan

AlgeriaArmenia

Azerbaijan

Benin

Burkina Faso

Burundi China

Egypt

Eritrea

Ethiopia Ghana

India

Iran

Israel

Japan

Jordan

Kenya

Korea Dem People's Rep

Korea Rep

Lebanon

Lesotho

Libya

Malawi

Mauritania

Mauritius

Morocco

NigerNigeria

Pakistan

Rwanda

Saudi Arabia

Senegal

Somalia

South Africa

Sri Lanka

SyriaTanzania

Togo

Tunisia

Turkey

Uganda

Emirates

Uzbekistan

Yemen

Zimbabwe

From Yang et al. 2003

5

Water availability and cereal import Water availability and cereal import comparison between 1980–84 and 1995–99comparison between 1980–84 and 1995–99

Adapted from Yang et al. 2003

Annual water requirement per capita forhousehold, services, industrial activities

(average 1990–95)

7

Annual water requirement Annual water requirement per personper person

Sufficient > 1700 m3

Water stress 1000 - 1700 m3

Scarcity 500 - 1000 m3

Extreme scarcity < 500 m3

From Falkenmark & Widstrand, 1992

8

Water availability and cereal import Water availability and cereal import comparison between 1980–84 and 1995–99comparison between 1980–84 and 1995–99

Adapted from Yang et al. 2003

9

Estimated annual world Estimated annual world water use totalwater use total

and by sector 1900–2000and by sector 1900–2000

From Postel, 1992

Water needed to produceWater needed to produce1 kg of plant material (dry 1 kg of plant material (dry

weight)weight)

10

Sorghum 250 LiterCorn 350 LiterClover 460 LiterWheat 500 LiterPotatoes 636 LiterCucumber 713 LiterAlfalfa 900 Liter

11

Meat productionMeat productionAnimals convert 5 to 15 % of the energy content of plant material into meat. The average is 10 percent.

12

Projection of water availabilityProjection of water availability

From Zehnder, 1999

Relationship of water-use efficiency to grain yield

1 2 3 4 5 6 7 8

0.2

0.4

0.6

0.8

1.0

1.2

Grain yield (ton/ha)

Wat

er u

se e

ffic

ienc

y (k

g/m

3 )

IrrigatedDryland

Y=0.259X – 0.016X2

R2=0.88

From: Musick et al. 1994

Crop yield

Yields of selected cereals (ton/ha) average 1999 - 2003

Australia China EU (25) USA

Barley 1.87 3.39 4.19 3.14

Maize 5.10 4.81 7.85 8.55

Rice 9.15 6.20 6.47 7.14

Wheat 1.78 3.83 5.61 2.75

According to FAO, 2004

Situation 2000

From Zehnder, 2002

Virtual water flows by regions(average over the period 1997–

2001)Unit: cubic km

From Yang et al. submitted

Exporter Importer

N America 73 E Asia 149

30 C America 64

22 N&W Africa 58

17 M East 55

27 Others 71

S America 30 W Europe 26

21 E Asia 25

18 M East 35

12 N&W Africa 21

15 Others 38

Oceania 15 E Asia 20

11 S-E Asia 24

10 M East 14

13 Others 24

Situation 2025

From Zehnder, 2002

18

Virtual water as part of a country‘s water resourceVirtual water as part of a country‘s water resource

ETET~~8.48.4

Fossil Fossil groundwatergroundwater

0.20.2

DesalinationDesalination0.210.21

Virtual water exp.Virtual water exp.approx. 0.35approx. 0.35

Virtual water imp.Virtual water imp.approx. 6.0approx. 6.0

RainRain9.29.2

DischargeDischarge0.50.5 External supplyExternal supply

1.031.03

IsraelIsrael

SingaporeSingaporeRainRain1.71.7

ETET1.31.3 from Malaysiafrom Malaysia

0.580.58

DesalinationDesalination0.150.15Virtual water imp.Virtual water imp.

approx. 4.0approx. 4.0 Run-offRun-off0.150.15

DischargeDischarge0.340.34

Numbers are in km3/yr

Water (Woda)

by Wislawa Szymborska

A drop of rain fell on my hand,

condensed from the Ganges and the Nile,

from the heavenward ascending hoarfrost on the whiskers of a seal,

from the water of broken jugs in the cities of Ys and Tyre.

On my index finger

the Caspian Sea is the open sea,

and the Pacific meekly flows into the Rudawa,

that very same river that floated as a cloud over Paris

in the year of seventeen hundred and sixty four

on the seventh of May at three in the morning.

There are not lips enough to utter

your fugitive names, O water.

You were in baptismal fonts and in the baths of courtesans.

In shrouds, in love-enshrouded kisses.

Eating away at stones, nourishing the rainbows.

In the sweat of dew and pyramids, of lilacs.

How much lightness there is in a drop of rain.

How delicately does the world touch me.

Whatever whenever wherever has happened

is written on the water of Chicago.

Someone was drowning, someone dying called for you.

That was long ago and that was yesterday.

Houses you extinguished, houses you carried off

like trees, forests like towns.

Someone was drowning, someone dying called for you.

That was long ago and that was yesterday.

Houses you extinguished, houses you carried off

like trees, forests like towns.

Someone was drowning, someone dying called for you.

That was long ago and that was yesterday.

Houses you extinguished, houses you carried off

like trees, forests like towns.

You were in baptismal fonts and in the baths of courtesans.

In shrouds, in love-enshrouded kisses.

Eating away at stones, nourishing the rainbows.

In the sweat of dew and pyramids, of lilacs.

How much lightness there is in a drop of rain.

How delicately does the world touch me.

Whatever whenever wherever has happened

is written on the water of Babel [Chicago].

Conclusions Water is increasingly becoming an economic

driving force. Economic and political interdependence is

growing. Economic power of less developed countries

needs strengthening.

Increased use of herbicides, insecticides, nutrients, genetically modified crops.

Significantly more water reuse can be expected.

Closure• Environmental problems and their solutions

involve complex technological, societal, cultural, economic, and political aspects.

• Environmental engineers and scientists must be comfortable traversing both the technical and the complex social terrain.

• Environmental science and technology can help to alleviate global environmental crises and contribute to world stability.

• We should do much more to save the lives of millions of children who die from easily preventable water-borne diarrheal diseases.

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24

6 great challenges in the water area6 great challenges in the water area

Good water quality fora growing population

Enoughfood for all

Water infrastructure(distribution & collection)

Solution for waterconflicts and fair

water share for all

Distribution betweenhumans and ecosystems

Water induced disastersDisaster protection