Transcript 20090223111639629

Sustaining Groundwater
Irrigation Economies:
China’s Challenge and
Global Experience
Explosive Growth in Groundwater Use
• Powerful manifestation of growing water
scarcity;
• Meteoric growth after 1960
• Of the 1000 km3 /year of global groundwater
use, over 800 km3 in agriculture; 600 in South
Asia and North China;
• Of the 300 m ha of global irrigation, over 1/3rd
is from groundwater wells.
• Protecting groundwater is critical for future
supply of domestic water needs.
Four Groundwater Socio-Ecologies
(GwSEs)
Habitat-Support GwSEs
Where: Most cities, towns and villages
Driver: Population Density and Industry
Challenge: Depletion; Land
Subsidence; Pollution
Non-Renewable GwSEs
Where: Arid and Semi-arid Regions;
MENA; Nubian
Driver: Urban Growth and Agriculture
Danger zone
Challenge:
Planned utilization of a
nonrenewable resource
Wealth-Creating GwSEs
Livelihoods-Support GwSEs
Where: Western US; Israel; Turkey;
Spain; S. Africa; Morocco; Tunisia
Driver: Industrial, High-value Agriculture
Challenge: Depletion; Drying up of
wetlands and streams; Non-point
pollution
Where: India, Pakistan, Nepal,
Bangladesh, North China plains
Driver: Small-holder subsistence
Agriculture
Challenge: Sustaining massive
livelihoods and protecting the resource
Growth in Population Density around the world (people/km2) , 1700 – 1990
Contrary to
popular notion,
population growth
over past 300
years occurred in
semi-arid areas..
Source: International Institute of Applied Systems Analysis (IIASA)
Expanding Cropland 1700-1990
Fraction of grid cell in croplands
Because surface irrigation occurs in
river valleys, we often think that gw
irrigation too would concentrate in
regions of abundant recharge..
Source: International Institute of Applied Systems Analysis (IIASA)
Long-term average
groundwater recharge
GW intensification has had
little to do with resource
Endowments; but with
Population pressure..
Malthus
Versus
Boserup
Source: Döll, P., Lehner, B., Kaspar, F. (2002): Global modeling of groundwater
recharge. In Schmitz, G.H. (ed.): Proceedings of Third International
Conference on Water Resources and the Environment Research, Technical
University of Dresden, Germany, ISBN 3-934253-17-2, Vol. I, 27-31
Growth in groundwater use in selected countries
US
W.Europe
(author's estimates)
Spain
300
Mexico
North China farmers
have drastically
increased their
groundwater use
250
China
India
cubic km/year
200
Pakistan
150
Banglade
Sri Lanka
100
Vietnam
50
Ghana
South Afric
0
1940
1950
1960
1970
1980
1990
2000
2010
Tunisia
Groundw ate r irrigate d are a in countrie s w ith inte ns ive
groundw ate r us e in agriculture (FAO Aquas tat 2003 and
othe r s ource s )
25000.00
20000.00
15000.00
000 ha
30000.00
According to FAO, gw
irrigated area in India,
China, Pakistan, B’desh and
Nepal together is larger
than anywhere else in the
world...
10000.00
0.00
Azerbaijan
Peru
Nepal
Egypt
Philippines
Korea, Dem People's
Iraq
South Africa
Tunisia
Uzbekistan
Kazakhstan
Afghanistan
Morocco
Argentina
Cuba
Yemen
Japan
Brazil
Syrian Arab Republic
Turkey
Saudi Arabia
Mexico
Bangladesh
Iran, Islamic Rep of
Pakistan
USA
China
India
5000.00
30000
45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
20000
15000
10000
5000
0
India
USA
China
Pakistan
Iran
Bangladesh
Mexico
Saudi
Italy
Turkey
Syria
Brazil
Libya
Morocco
Argentina
Cuba
Yemen
Afghanistan
Egypt
Algeria
Australia
Uzbekistan
Tunisia
Iraq
South Korea
Kazakhstan
'000 ha
25000
Area under groundwater irrigation
% of farming area under groundwater irrigation
%
Figure Top 20 Groundwater Irrigation Countries in the World
(FAO AQUASTST 2003)
In sum, groundwater boom in Asia is driven by:
•
•
•
•
•
•
•
Tubewell technology
High population pressure on land;
Semi-arid, monsoon climate
Green Revolution technology
Pump and tubewell technology
Failure of public irrigation systems
Electricity subsidies (in India, Mexico, Syria)
Groundwater irrigation drives
national and regional politics
because it affects majority of
country’s population..
Country
Annual
groundwater
use (km3)
No of
Agricultural
Groundwater
Structures
(million)
Extraction/
structure
(m3/year)
% of
population
dependent
directly or
indirectly on
groundwater
irrigation
India
200-210
21
7900
55-60
Pakistan-Punjab
45
0.5
90000
60-65
China
75-90
3.5
21500
22-25
Iran
29
0.5
58000
12-18
Mexico
40
0.07
414285
5-6
USA
100
0.2
500,000
<1-2
Beneficial impacts:
• Biggest alleviator of rural poverty
• Driver of agricultural productivity
growth
• Spatial equity in access to irrigation
• High water productivity
• Socio-economic and political
stability
• Mobilizes private capital
Negative Impacts.
• Groundwater depletion;
• Increased pumping costs and energy use;
• Drying up of lean season stream-flows and
wetlands;
• Threat of Secondary salinization
• Geo-genic contaminants: arsenic and
fluoride;
Informalization of Irrigation..
• In well-managed water economies, water users
are mediated through formal water service
providers; and self-supply is minimal.
• The groundwater boom has made some of
Asia’s water economies highly informal. Most
water users have little or no contact with public
systems; so they are difficult to reach and
regulate..
Reigning in the booming
groundwater economy..
China’s new policy
of ‘water withdrawal
permits’ is designed
to formalize
groundwater
irrigation economy..
Water saving technologies—drips and mulching-are taking off in cotton and other crops..
To what extent will these
ease aggregate pressure
on China’s groundwater
aquifers unclear.. Some
argue only reducing
irrigated areas will help..
But this will be difficult in
the short run.
IWMI Assessment of
Mexican Water Reforms
•
‘Concessions’: Water Rights and volumes
assigned ; Tradable; COTAS
• Mexico has around 100,000 irrigation
tubewells; despite that, monitoring
concessions and penalizing violations has
proved difficult;
• Doubtful if reforms have contained
groundwater extraction
• Mexico is now turning to differential energy
prices as a mechanism to penalize overdrafters.
Challenge of groundwater governance..


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Banning private wells would be difficult to implement; crowd them
out by improving public water supply
Regulating final users is difficult; facilitate mediating agencies to
emerge, and regulate them. China has lessons to offer.
Pricing agricultural groundwater use is infeasible; instead, use
energy pricing and supply to manage agricultural groundwater
draft.
No alternative to improved supply side management: better rainwater capture and recharge, imported surface water in lieu of
groundwater pumping.
Grow the economy, take pressure off land, formalize the water
sector.
Transformation of Informal Water Economies with Overall Economic Growth
% of users in the
formal sector
Stage I: Completely
Informal
Stage II: Largely
Informal
Stage III: Formalizing
Stage IV: Highly Formal
Water Industry
<5%
5-35%
35-75%
75-95%
Examples
Sub-Saharan Africa
India, Pakistan,
Bangladesh
Mexico, Thailand,
Turkey, Eastern China
USA, Canada, Western
Europe, Australia
Dominant mode of
water service
provision
Self-supply and informal
mutual-help community
institutions
Partial Public
Provisioning but selfsupply dominates
Private-public provisioning;
attempts to improve service
and manage the resource
Rise of modern water
industry; High Intermediation;
self-supply disappears
Concerns of the
Governments
Infrastructure creation in
Welfare Mode
Infrastructure and Water
services, especially in Urban
areas in a welfare mode
Infrastructure and service in
towns and villages; Cost
recovery; Resource
protection
Integrated mgt. of water
infrastructure, service
and resource; Resource
protection
Institutional
Arrangements
Self-help; mutual help and
feudal institutions
dominate
Informal Markets; Mutual
help and community
management institutions
Organized service providers;
self-supply declines;
informal institutions decline
Self-supply disappears;
all users get served by
modern water industry.
Human, technical,
financial resources
used/km3 of water
diversion
% of total water use
self-supplied
Rural population as %
of total
Cost of domestic
water as % of per
caput income
Cost of water service
provision