Water Policy for Food Security: A Global Conference, Davis, CA, October 5-6 at UC Davis

1. Groundwater Use and Depletion in Asia
Implications for Irrigated Agriculture
Tingju Zhu
International Food Policy Research Institute
Washington, DC
Water Policy for Food Security: A Global Conference, Davis, CA, October 5-6 at UC Davis

2.  The world's most populous continent, with 4.4 billion
population in 2014
 Accounting for 70 percent of the world’s net irrigated
area
 With 20 million wells, South Asia alone accounts for
nearly half of global groundwater used for irrigation
 Asia is responsible for the largest share of food
production from depleting groundwater, especially in
northwestern India and North China Plain
 High vulnerability to climate change – Glacier-fed rivers
and major river deltas critical for agriculture are to be
affected
 Growing population and changing to more water-
intensive diet
Asia – Population, Water, and Agriculture

3. Hydro-climatology, Irrigation, and Irrigated Areas
Source: 1) Precipitation from GPCC v5. 2) PET and runoff simulated by the IMPACT Global Hydrological Model (IGHM) for
1971-2000. 3) Irrigated area share based on GMIA database by Siebert et al. (2007).
• IGP
• NCP
• Deltas

4. 78
80
82
84
86
88
90
1000
1200
1400
1600
1800
2000
2200
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 2055
Asia - Irrigation consumption World - Irrigation consumption
Asia - Share of irrigation water consumption World - Share of irrigation water consumption
Irrigation Water Consumption and Share in Total
Water Consumption – Asia and World
Source: IMPACT3.2 baseline projection
Notes: Consumption in km3/yr

5. 0
200
400
600
800
1000
1200
2000 2030 2050
ConsumptiveUseinIrrigation(km3/yr)
Other
Vegetables
Cotton
Maize
Sugarcane
Wheat
Rice
Irrigation Water Consumption by Crop in Asia
Source: IMPACT model projections in IFPRI report submitted to ADB (2013)

6. 0
50
100
150
200
250
2000 2030 2050
ConsumptiveUseinIrrigation(km3/yr)
Other
Soybean
Cotton
Vegetables
Maize
Wheat
Rice
0
50
100
150
200
250
300
350
400
450
500
2000 2030 2050
ConsumptiveUseinIrrigation(km3/yr)
Other
Sub-tropical
fruit
Cotton
Sugarcane
Rice
Wheat
China India
Irrigation Water Consumption by Crop
in China and India
Source: IMPACT model projections in IFPRI report submitted to ADB (2013)

7. Groundwater Irrigated area in Asia
Source: Irrigated area share based on GMIA database by Siebert et al. (2007).

8. Groundwater Withdrawal in Asia: 1940-2010
Source: Shah et al. (2007)

9. Groundwater Abstraction by Region and Crop
Australia/Ocean
ia
0%
Central Asia
2%
East Asia
14% Latin America
and the
Caribbean
2%
Near East/North
Africa
16%
OECD
23%
Other European
Countries
1%
South Asia
41%
Sub-Saharan
Africa
1%
Regions
Beverage and
spice crops
19%
Cereals
43%
Leguminous
crops
4%
NonFood
Crops
9%
Oilseed Crop
8%
Other Crops
0%
Roots and
Tubers
2%
Sugar
Crops
7%
Vegetables
and Fruits
8%
Crop Groups
Source: IWMI and IFPRI analysis, work in progress

10. Groundwater Depletion by Region and Crop
Australia/Oceani
a
0%
Central Asia
2%
East Asia
10%
Latin America
and the
Caribbean
1%
Near East/North
Africa
23%
OECD
24%Other European
Countries
1%
South Asia
38%
Sub-Saharan
Africa
1%
Regions
Beverage and
spice crops
11%
Cereals
49%
Leguminous
crops
4%
NonFood Crops
12%
Oilseed Crop
7%
Other
Crops
0%
Roots and
Tubers
2%
Sugar Crops
6%
Vegetables and
Fruits
9%
Crop Groups
Source: IWMI and IFPRI analysis, work in progress

11. Groundwater Depletion in Indus and
Ganges Basins (GRACE and
Reconstructed Depletion in Dry Season)
Oct-Apr
Oct-Apr
Source: IFPRI and UCF, work in progress

12. Drought Frequency in the Indus and Ganges and
Reconstructed Precipitation
Drought frequency (as a percentage) during the Period of 1300-1899 (left) and 1900-2010 (right)
Indus basin Ganges basin
Source: IFPRI and UCF, in Davtalab et al. (2015)

13. Source: Gao et al. (2013)
Groundwater Depletion in North China Plain

14. Groundwater Management in the Indo-Gangetic
Plains
Bihar
Western IGP:
• High investment in
infrastructure;
• Effective institutions and policy
support
• Intensive agriculture (e.g.
agrochemicals and ground-
water irrigation)
• Surplus food production
responsible for regional food
security
• Seasonal in-migration of male
labor
Eastern IGP:
• Relatively low productivity and poor infrastructure
• Limited capacity for private investment
• Prone to flooding and drought
• Food deficit region; out-migration of male labor to other
regions
Food-Water-Energy Nexus
Energy Subsidies
Groundwater
development
challenges

15. Groundwater irrigation Challenges in Eastern IGP
(Vaishali, Bihar)
• Irrigation in Vaishali almost entirely depends on
groundwater; surface water irrigation infrastructure
existing but not functional
• Bihar is an electricity-scarce state; irrigation in
Vaishali has to rely on diesel pumps
• Diesel price is high (~Rs52/l; new pump set
Rs25K~30K)
• Ownership of tubewells and pump sets
• Farmers have little capacity in private investment
• Farmers indicate delayed Monsoon can cause ~80%
production cost increase (rice + wheat)

16. Additional Irrigation for Crop Intensification in
China?
Source: IFPRI and CAAS, work in progress by Yu et al.
Irrigation water
use in China
remains roughly
unchanged for
more than two
decades.
South-to-North
Water Transfer
Project’s water
too expensive
for agriculture.
Investment in
rural water
infrastructure
has been
increased since
2011.
Pilot sites for
market-based
water transfers
in 7 provinces,
by MWR.

17. Is water-saving irrigation technologies a
solution?

18.  Lack of Incentives: Farmers concern economic return
and production risks, not necessarily irrigation water-
saving
 Technologies need to be adapted to local settings
 Technologies need to go hand in hand with agricultural
extension
 Move from water-saving to cost-effectiveness,
including labor-saving, energy-saving, higher yield and
better crop quality, and reduced production risks
 Information and institutional development
Adoption of Irrigation Technologies for Water-
saving in Asia

19. Conclusions
 Groundwater is critical for agricultural production in Asia,
with increasing withdrawal trends in many countries.
 Depletion of groundwater is a growing challenge to
sustainable water use and agricultural production,
especially in northwestern India and North China Plain.
 Groundwater will become only more important in the
future, with decreasing snowpack (i.e. Himalayas rivers)
and increasing hydroclimatic variability.
 Enhanced monitoring, assessment, and holistic
multisector policies are critical for sustainable
groundwater use and irrigation in Asia.