Karen G. Villholtha, Aditya Soodb, Nirosha Liyanagec, Tingju Zhud

a Principal Researcher, IWMI, South Africab Senior Researcher, IWMI, Sri Lanka

c GIS Consultant, IWMI, Sri Lankad Senior Research Staff, IFPRI, Washington DC

GLOBAL FOOD PRODUCTION - THE CONTRIBUTION OF GROUNDWATER AND DEPLETING AQUIFERS

26th IUGG General Assembly 2015Prague, Czech Republic

How much does groundwater contribute to global food production?

How much of this is unsustainable?

Objective of This Research

S

R

D

Natural conditions

Averaged over long term, R=D and S is constant

S

R

D

Stable groundwater pumping

Qnet is equivalent to reduction in D and S

Qnet

S

R

D

Unsustainable condition

Qnet is greater than R, D reduces to 0 and S decreases continuosly

Qnet

Fundamental groundwater balance

Groundwater depletion occurs when the rate of

groundwater abstraction is

greater than the rate of

replenishment

Source:Shah et al., 2007

Gro

undw

ater

with

draw

al (c

ubic

km

per

ye

ar)

Development in groundwater withdrawal in selected countries

19601962

19641966

19681970

19721974

19761978

19801982

19841986

19881990

19921994

19961998

20000

50,000

100,000

150,000

200,000

250,000

300,000

Mm

3//y

ear

Total groundwater depletion at global scale

Source: Wada et al., 2012

Results from the PCR-GLOBWBmodel

Depletion = Abstraction - Recharge

• Larger than 10%, inferred from Shah et al. (2007)

• 40% of all cultivated land under irrigation is ‘water well equipped’ (Foster and Shah, 2012)

• About 10% of global food production depends on using mined GW (FAO, 2003)

• In China, 15-27% of total national food production (incl. rainfed) is from mined GW (Grogan et al., 2015)

Earlier Estimates of the Role of GW in Global Irrigated Food Production

SPAM data/map Food Production

and Harvested Area mapping

PCR-GLOBWB data/mapGroundwater Abstraction

&Recharge

FAO data/mapPercentage of Irrigated Area by Groundwater

FINAL PRODUCTFood Production and Harvested

Area dependent on GW abstraction and GW depletion

METHODOLOGYGIS analysis

Grid maps of Agricultural Water Demand & Total

Water Demand

COUNTRY GROUPING

CROP GROUPING

Crop Group Crop Name

Beverage and spice crops

arabica coffeecocoarobusta coffetea

Cereals

barleymaizeother cerealspearl milletricesmall milletsorghumwheat

Leguminous crops

other pulsesbeanchickpeacowpealentilpigeonpea

NonFood Cropscottonother fibre cropstobacco

Crop Group Crop Name

Oilseed Crop

coconutgroundnutoilpalmother oil cropsrapeseedsesame seedsoybeansunflower

Other Crops rest of crops

Roots and Tubers

cassavaother rootspotatosweet potatoyams

Sugar Cropssugarbeetsugarcane

Vegetables and Fruits

bananaplantaintemperate fruittropical fruitvegetables

Total Crop Production :Region wise

*without Australia, New Zealand & Chile

Total Physical Area: 1136.76 Million Hectare

Total Harvested Area: 1240.80 Million Hectare

Total Production: 6810.97 Million Metric Ton

*without Australia, New Zealand & Chile

Total Physical Area: 1136.76 Million Hectare

Total Harvested Area: 1240.80 Million Hectare

Total Production: 1136.76 Million Metric Ton

Total Crop Production :Crop Group wise

Rainfed vs. Irrigated

Percentage of 5 arc min grid cell area equipped for irrigation with groundwater out of total irrigated area

Validate FAO and SPAM

FAO “area in hectares that is irrigated by groundwater”

(Step 2) (2005 at 5’ grid)

Irrigated Physical Area in SPAM (Step 1)

(2005 at 5’ grid)Action

Some area

Area more than or equal to FAO

Use area equal to FAO. Rest is from SW. The area will be distributed among crops based on the original ratio of crop area in

SPAM.

Area less than FAO Use area of SPAM and report the difference

No area Use no area and report the difference

No areaSome area Set it to zero. Assume it to be SW

irrigation. Note the difference.

No area No action (leave as blank)

Physical Area Irrigated by Groundwater

Regions Area (Million hectare)

Percentage of Irrigated Area

Australia/Oceania 0.2 52.4%Central Asia 0.5 17.3%

East Asia 15.5 26.5%Latin America and the Caribbean 1.8 19.5%

Near East/North Africa 6.6 33.5%OECD* 19.6 64.1%

Other European Countries 0.7 20.0%South Asia 37.9 52.6%

Sub-Saharan Africa 0.3 5.5%Grand Total 83.12 41.0%

Areas in Greenland and other drier areas show depletion but also have negative recharge - removed

Groundwater Abstraction and Depletion - Region-wise (all uses)

Region Abstraction (Km3)

Depletion (Km3)

Depletion as %age of

Abstraction

Australia/Oceania 3.01 1.0 33.3

Central Asia 13.8 7.9 57.0

East Asia 117.9 37.5 31.8

Latin America and the Caribbean 19.1 2.6 13.4

Near East/North Africa 96.9 74.9 77.3

OECD* 201.0 86.2 42.9

Other European Countries 23.1 6.8 29.5

South Asia 252.5 122.0 48.3

Sub-Saharan Africa 5.6 2.4 42.9

Total 733.0 341.27 46.6

For year 2001

* without Australia, New Zealand & Chile

Groundwater Abstraction/Depletion for Agriculture

Original Data Processed Data

x

Temporal: 2001 Spatial: 0.5 o

Groundwater Abstraction

Temporal: 2001 Spatial: 0.5 o

Groundwater Depletion

Temporal: 2001 Spatial: 0.5 o

Groundwater Abstraction for Agriculture

Temporal: 2001 Spatial: 0.5 o

Groundwater Depletion for Agriculture

Validate GW abstraction/depletion with SPAM Groundwater Irrigated maps

Agricultural - GW abstraction/depletion

(2001 at 0.5o grid)

SPAM-GW-Irrigated Map(2005 at 5’ grid) Action

Yes

1 or more grids with GW-Irrigated Area

Distribute GW abstraction and depletion proportionally between

grids equipped for irrigation.

No grids with GW-Irrigated Area Leave Blank. Assume GW abstraction for non-agriculture use.

No1 or more grids with GW-

Irrigated Area Leave Blank – Report Error

No grids with GW-Irrigated Area Leave Blank

Region Abstraction (Km3)

Depletion (Km3)

Depletion as %age of

AbstractionAustralia/Oceania 1.6 0.7 43.9

Central Asia 8.8 6.7 76.6

East Asia 78.2 31.4 40.1Latin America and the Caribbean 10.7 2.1 20.0

Near East/North Africa 89.0 69.2 77.7

OECD* 125.7 73.8 58.7Other European Countries 7.7 2.9 37.5

South Asia 231.4 116.9 50.5

Sub-Saharan Africa 4.1 2.00 49.1

Total 557.26 305.7 54.9 For year 2001

* without Australia, New Zealand & Chile

Groundwater Abstraction and Depletion - Region-wise (agriculture only)

GW Abstraction for Agriculture

GW Depletion for Agriculture

Distributing GW abstracted and depleted between irrigated crops

Original Data Processed Data

Temporal: 2001 Spatial: 5’ Temporal: 2001 Spatial: 5’

Groundwater Abstraction Map

Groundwater Depletion Map

Groundwater Abstraction Map

𝑇𝑜𝑡𝑎𝑙 𝑑𝑒𝑝𝑙𝑒𝑡𝑖𝑜𝑛 (𝑎𝑏𝑠𝑡𝑟𝑎𝑐𝑡𝑖𝑜𝑛 )𝑝𝑒𝑟𝑐𝑟𝑜𝑝∗ 𝐴𝑐 𝐾 𝑐

∑𝑐=1

𝑐=𝑛

𝐴𝑐𝐾 𝑐

Groundwater Depletion Map

42 Layers (One for each crop):

Used harvested area Water productivity due to

groundwater irrigation considered to be double than that due to surface water irrigation

CROP PRODUCTION FROM ABSTRACTED GROUNDWATER

Australia/Oceania2%

Central Asia0%

East Asia17%

Latin America and the Car-

ibbean7%

Near East/North Africa

4%OECD23%

Other European Coun-tries1%

South Asia45%

Sub-Saharan Africa1%

Regions

Beverage and spice crops0%

Cereals44%

Leguminous crops0%

NonFood Crops3%

Oilseed Crop3%

Other Crops0%

Roots and Tubers7%

Sugar Crops36%

Vegetables and Fruits7%

Crop Groups

CROP PRODUCTION FROM DEPLETED GROUNDWATER

Australia/Oceania0%

Central Asia0%

East Asia19%

Latin America and the Car-

ibbean1%

Near East/North Africa

8%

OECD23%

Other European Countries

0%

South Asia46%

Sub-Saharan Africa1%

Regions

Beverage and spice crops

0%

Cereals48%

Leguminous crops1%

NonFood Crops4%

Oilseed Crop2%

Other Crops0%

Roots and Tubers

8%

Sugar Crops29%

Vegetables and Fruits

7%

Crop Groups

DISTRIBUTION OF HARVESTED AREA IRRIGATED BY ABSTRACTED GROUNDWATER

Beverage and spice crops0%

Cereals71%

Leguminous crops

3%

NonFood Crops

6%

Oilseed Crop10%

Other Crops0%

Roots and Tubers

2%

Sugar Crops4%

Vegetables and Fruits3%

Crop Group

Australia/Oceania0%

Central Asia0%

East Asia20%

Latin America and the Car-

ibbean2%

Near East/North Africa

6%

OECD (without Australia, New

Zealand & Chile)19%

Other European Coun-tries1%

South Asia50%

Sub-Saharan Africa0%

Region

DISTRIBUTION OF HARVESTED AREA IRRIGATED BY DEPLETED GROUNDWATER

Beverage and spice crops0%

Cereals71%

Leguminous crops

3%

NonFood Crops

9%

Oilseed Crop8%

Other Crops0%

Roots and Tubers

2%

Sugar Crops3%

Vegetables and Fruits3%

Crop Group

Australia/Oceania0%

Central Asia1%

East Asia23%

Latin America and the Car-

ibbean0%

Near East/North Africa

11%

OECD (without Aus-tralia, New Zealand &

Chile)18%

Other European Coun-tries0%

South Asia46%

Sub-Saharan Africa0%

Region

ProductionOf Total

(Rainfed & Irrigated)

Of Irrigated Of Irrigated by Groundwater

From abstracted GW 13.3% 44.4%

From Depleted GW 4.3% 14.5% 32.6%

AGRICULTURAL PRODUCTION SUMMARY

HARVESTED AREA SUMMARY

8.4% of all agriculture harvested area is irrigated by groundwater.

41% of irrigated harvested area is irrigated by groundwater.

35% of the groundwater irrigated harvested area is from depleted groundwater.

Shortcomings

• Dataset for GW abstraction and depletion at 0.5 degrees, rather than at 5 minutes

• GW depletion data from 2001 where as the crop related data from 2005

44 % of global irrigated agriculture production derives from GW irrigation

14.5 % of global irrigated agriculture production derives from depleting groundwater

32.6 % of all GW-based agriculture production is based on unsustainable abstraction

Asia is responsible for the largest share of food production from depleting groundwater

Cereals and sugar crops are the GW-irrigated crops most widely grown unsustainably, in terms production

Results imply the critical importance of analysing and developing congruent policies at multiple levels that account for the nexus between groundwater and food security

Conclusions

Acknowledgement

• Dr. Rens van Beek & Dr. Yoshi Wada, Geosciences, Univ. of Utrecht, PCR-GLOBWB model groundwater data set

• Ulrike Wood-Sichra and Liangzhi You, IFPRI, SPAM data set

Brown, L.R., 2011. World on the Edge: How to Prevent Environmental and Economic Collapse, Earth Policy Institute. W.W. Norton and Company. ISBN: 978-0-393-33949-9.

FAO, 2003. The Irrigation Challenge. IIPTRID Issue Paper 4. Sep. 2003.

Foster, S. and T. Shah, 2012. Groundwater Resources and Irrigated Agriculture – making a beneficial relation more sustainable. Perspectives Paper. Global Warter Partnership.

Morris, B.L., A.R.L. Lawrence, P.J.C. Chilton, B. Adams, R.C. Calow, B.A. Klinck, B A. , 2003. Groundwater and its Susceptibility to Degradation: A Global Assessment of the Problem and Options for Management. Early Warning and Assessment Report Series, RS. 03-3. United Nations Environment Programme, Nairobi, Kenya.

Shah, T., J.J. Burke, and K.G. Villholth, 2007. Groundwater: a global assessment of scale and significance. Chapter 10, 395-423. In: D. Molden (Ed.): Water for Food, Water for Life. Comprehensive Assessment of Water Management in Agriculture Synthesis Report. Earthscan. ISBN: 978-1-84407-396-2.

Siebert, S., J. Burke, J.M. Faures, K. Frenken, J. Hoogeveen, P. Döll, and F.T. Portmann, 2010. Groundwater use for irrigation - a global inventory. Hydrol. Earth Syst. Sci., 14, 1863-1880. doi:10.5194/hess-14-1863-2010.

Wada,Y., L.P.H. van Beek, and M.F.P. Bierkens, 2012. Nonsustainable groundwater sustaining irrigation: A global assessment. Wat. Res. Resear., 48, W00L06, doi:10.1029/2011WR010562.

References

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