1 World Water Resources in the 21 Century - JST...6In the course of the century, water supplies stored in glaciers and snow cover are projected to decline, reducing water availability

http://hydro.iis.u-tokyo.ac.jp/ 1

Taikan OkiInstitute of Industrial Science, The University of Tokyo

World Water Resourcesin the 21st Century

Global Innovation Ecosystem (GIES) 2008 WorkshopNational Center of Sciences Building, Tokyo, March 14th, 2008


World Water Issues

Indispensable water for livesOne in five of the world population does not have access to safeand affordable drinking water (20L/d/c within 1km).

Each year 3-4 million people die because of waterborne diseases

Profitable water for agriculture and industryTotal withdrawals 3,800km3(1995) 4,300-5,200km3(2025)

Comfortable water for human being and ecosystemsClimate Change and Urbanization water hazard risksInternational conflicts because of water issues?


Future ProjectionFuture Projectionthrough the 21through the 21stst CenturyCentury

Changes considered include:Water demand for domestic, industrial, and irrigation sectors.

Population (SRES)Urban and rural areas separated

GDP (SRES)Improvement of reuse (SRES)

Climate change (SRES)


A：Economic growth oriented

B：Environmentally oriented

１：Globalization

２：Regionalization

A1：Fast development in economy and population. Technological transfer as well. A1b will use use various energy from multiple sources developed.

A2：Regions are isolated. Slow technological transfer and culture. Population growth will be extremely high.

B1：Globalization and similar population growth as A1, but environmentally conscious and technological transfer and development of new technology and new energy are fast. Sustainability in economy, society, and environment are enhanced globally.

B2：Less population than A2 but more than A1 and B1. Sustainability is focused but solved regionally.

IPCC SRES Scenarios

http://hydro.iis.u-tokyo.ac.jp/ 5World Food Production and Supply

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

2.1

2.2

2.3

2.4

2.5

1960 1965 1970 1975 1980 1985 1990 1995 2000

Year

Rat

io t

o t

he 1

961 V

alue

Population-Estimates

Agricultural Area

Irrigated Area

Area Harv: Cereals, Total

Yield: Cereals, Total

Production: Cereals, Total

Cal/Cap/Day

“irrigated land, which is 16% of cropland,

produces 40% of crops”

(based on FAOSTAT & AQUASTAT)

World Food Production and Supply


GDP/capita and domestic water use

Future Domestic Water Use=Future Estimate +D

where D is the bias error,D=Statistics in 1900 –

Estimate for 1990

Assumptions：1 Domestic water use in

developing countries will increase associated with the increase of GDP.

2 Life style in domestic water use is calibrated by simple manner for countries with statistics of the current domestic water use.

1

10

100

1000

100 1000 10000 1000001人当たりGDP [1990年 USドル]

1990年

　1人

当た

り生

活用

取水

量[m

3/(人

・年

)]

Q : Domestic Water Use [m3 / capita/year ] G : GDP per person [US$ equivalent of year 1990]

989.32403169.2+

×G

Glog(Q) =

* Future GDP under SRES scenario was downscaled from GDP projection in 4 region in the world into each country by CIESIN.

GDP and Domestic Water Use

G

Q


Total water withdrawal and GDP for industry in each country are proportional.

Japan is an exception with high water use efficiency.

r = 0.788

slope = 51

0

20000

40000

60000

80000

100000

120000

0 200 400 600 800 1,000 1,200 1,400GDP(PPP) for Indus. /bilion $

Indu

s. w

ater

use

/m

ilion

m^3

Japan

Russia

CanadaFrance

KoreaUK

r = 0.935(0.967 exclud. Japan)

China

USA

( Japan)

slope = 74

0

50000

100000

150000

200000

250000

0 500 1,000 1,500 2,000 2,500 3,000

GDP(PPP) for Indus. /bilion $

Indu

s. w

ater

use

/m

ilion

m^3

3

Future IW＝Current IW ＊GDP Growth for Industry＊Improvement of water use efficiency

Future Projection

GDP and Industrial Withdrawals

(part of the left figure)


0

1000

2000

3000

4000

5000

6000

1980 2000 2020 2040 2060 2080Year

Wat

er d

eman

d (k

m3 /y

)

A1bA2B1

Agricultural water withdrawal

0

2

4

6

8

10

12

14

16

1980 2000 2020 2040 2060 2080 2100 2120

Year

Popula

tion (

billion) A1B1

A2

B2

Agricultural0

100

200

300

400

500

600

1980 2000 2020 2040 2060 2080 2100 2120

Year

World

GD

P (

Trillion U

S$ 1

990) A1b

A2

B1

B2

0500

1000150020002500300035004000

1980 2000 2020 2040 2060 2080

Wat

er d

eman

d (k

m3 /y

) A1bA2B1

0

200

400

600

800

1000

1200

1980 2000 2020 2040 2060 2080

Wat

er d

eman

d (k

m3 /y

)

A1bA2B1Domestic

Industrial

SRES basedPopulation (urban & rural), GDP, efficiencyClimate change

Global 0.5 degree grid distribution based

Population

GDP

Future Projection


Total Water Withdrawal (106m3/y)in 2050 (difference to Year 2000)

A1b(2055-2000)

(Shen, et. al, 2008, HSJ)

-5000 -200 -50 -5 5 50 200 1000 5000


（Lead Authors for the 4th Assessment Report of the IPCC, WG II, Chapter 3 “Freshwater resources and their management”）


Impacts of climate change on freshwater fesources

In the course of the century, water supplies stored in glaciers and snow cover are projected to decline, reducing water availability in regions supplied by melt water from major mountain ranges, where more than one-sixth of the world population currently lives.By mid-century, annual average river runoff and water availability are projected to increase by 10-40% at high latitudes and in some wet tropical areas, and decrease by 10-30% over some dry regions at mid-latitudes and in the dry tropics, some of which are presently water-stressed areas.Drought-affected areas will likely increase in extent. Heavyprecipitation events, which are very likely to increase in frequency, will augment flood risk.

（IPCC AR4, WGII, SPM, 2007）


(Nohara, et. al, 2006, J Hydrometeor.)

Changes in Annual River Discharge---Ensemble Mean of 15 GCM results for IPCC AR4 ---

Annual freshwater resources will increase and decrease due to climate change.

Decrease Increase(A1B)


(IPCC TAR, 2001)

Signals of CC could be detected through the change of the frequency of extreme events?

http://hydro.iis.u-tokyo.ac.jp/ 14Change in Drought Frequency

End of 21st centurycompared with 20th century

Drought: daily river discharge is belowthreshold of 10%

percentile

Hirabayashi et al., (in revision)Based on CCSR-NIES AOGCM

Change in Flood Frequency

End of 21st centurycompared with 20th century

Frequency in the 21st century of 100-

year floodin the 20th century

Increase Drought

Flood Increase Flood Decrease

Decrease Drought


Number of people underserious water stress

(Oki and Kanae, Science, 2006)

Rws= (W-S)/QAwc= Q/C (m3/y/c)

Q: How can we realize B1 society?

Rws in 2055 (A2)


Rws= (W-S)/Q

Water stress index in 2050

< 0.1

0.2 ~ 0.4> 0.4

0.1 ~ 0.2

MultiGCM/GSWP2

A1b

A2

B1


MultiGCM/GSWP2

Change in water stress index for 2050 (difference)

A1b

A2

B1

2055-2000

< -0.2-0.2 ~ -0.1-0.1 ~ 0.10.1 ~ 0.20.2 ~ 0.40.4 ~ 0.6

> 0.6

http://hydro.iis.u-tokyo.ac.jp/ 18Change in water stress index for 2050 (ratio)

MultiGCM/GSWP2

A1b

A2

B1

2055/2000

< 0.50.5 - 0.90.9 - 1.51.5 - 2.02.0 - 3.03.0 - 4.04.0 - 5.0

> 5.0


Impact of human activities on freshwater resources and their management, with climate

change being only one of multiple pressures

(IPCC AR4, WGII, Chapter 3, “Freshwater Resources and their Management”, 2006)


Adaptation OptionsSupply-side

Prospecting and extraction of groundwaterIncreasing storage capacity by building reservoirs and damsDesalination of sea waterExpansion of rain-water storageRemoval of invasive non-native vegetation from riparian areasWater transfer

(IPCC AR4, WGII Ch3, 2007)


Adaptation OptionsDemand-side

Improvement of water-use efficiency by recycling waterReduction in water demand for irrigation by changing the cropping calendar, crop mix, irrigation method, and area plantedReduction in water demand for irrigation by importing agricultural products, i.e., virtual waterPromotion of indigenous practices for sustainable water useExpanded use of water markets to reallocate water to highly valued usesExpanded use of economic incentives including metering and pricing to encourage water conservation

(IPCC AR4, WGII Ch3, 2007)

http://hydro.iis.u-tokyo.ac.jp/ 22Design Capacity

for 1/50 underClimate Change

DesignCapacity

for 1/50 underCurrent Climate

Current Capacity

Magnitude of possible hazard (e.g., flood level)

1/100

1/50

1/20

1/10

1/5

CurrentCondition

Capacity of counter measure to mitigate disaster (e.g., dike height)

1/50

1/20

1/10

1/5

1/2

UnderClimate Change

ClimateChange

Premium

The same safety level will be assured

with the “Climate Change Premium”


Support developingsustainability in a society

Water should not be dealt alone separated from food and energy.

Water

Energy Food

desalination

hydropower irrigation

virtual water trade

bio-fuel

cultivation

Limited Resources = “LAND”


MessagesScenario Projection:

The ultimate objectives of future-oriented world water resource assessments are to show the international community what will happen if we continue to manage our water resources as we do today and to indicate what actions may be needed to prevent undesirable outcomes. In that sense, studies of future world water resources are successful if their predictions based on business-as-usual are proven wrong.

Mitigation is also good for sustainable energy usage, and adaptation is also good for reduction of current vulnerabilities.

(Oki and Kanae, Science, 2006)

Documents

1 World Water Resources in the 21 Century - JST...6In the course of the century, water supplies stored in glaciers and snow cover are projected to decline, reducing water availability