Agricultural productivity and food security in the lower Mekong - - PowerPoint PPT Presentation

Agricultural productivity and food security in the lower Mekong Basin: impacts of climate change and options for adaptation

Presentation at the 1st Meeting of Climate Change Adaptation Demonstration Projects, 21-22 July 2011, Ho Chi Minh City, Vietnam

Dr Mohammed Mainuddin CSIRO Land and Water, Canberra, Australia

The Mekong

China Myanmar Laos Thailand Vietnam Cambodia

500 km

Luang Prabang Tonle Sap Phnom China Myanmar Laos Thailand Vietnam Cambodia

500 km 500 km

Luang Prabang Tonle Sap Phnom

• 6 countries, 4 in Mekong River

Agreement, China and Myanmar

• bservers
• ~65 m people, majority rural
• ~4,200 km long; 795,000 km2; 495,000

mcm discharge (495 km3)

Background: The Mekong Basin

• Agriculture, along with fisheries and forestry, employs 85% of

the people living in the Basin

• The population of the Mekong expected to increase from the

current 65 million to 90 million in 2050

• Proportion of urban dwellers will increase from 20% to about

40%

• Current economic growth is around 4.5% per annum
• These factors will drive great change in the Basin and the food

demand will increase greatly

• Climate change has emerged as one potential additional driver,

particularly in terms of more long-term changes

Climate threats?

• Climate change may affect the yield of

crop directly and also lead to increased demand for irrigation water in dry season - could reduce yields unless extra irrigation water

• Climate change may raise sea level,

leading to greater saline area in delta and less land for rice

• Climate change may also increase

extreme events such as flooding, drought and cyclones (both intensity and duration) having widespread damage

Importance

Sowe need to know;

• What are the potential impacts of climate change on crop

yield?

• What climatic parameters is having significant impact?
• What are the feasible adaptation strategies in both long-term

and short-term?

• How food security might be affected in the future considering

population growth?

The study

Here I present;

• Impacts of climate change on the yield of rainfed rice, irrigated

rice and Maize of the LMB (covers ~90% of the total crop harvested area of the basin)

• What parameters are having significant impact
• Results of testing of some simple adaptation strategies on

rainfed rice

• An analysis of food security of the basin (country-wise) at 2050

considering climate impact and population growth.

Climate model and scenario

• Climate change data used - projection based on ECHAM4

(European Centre Hamburg Model) General Circulation Model (GCM) from Max Planck Institute for Meteorology, Germany and downscaled using the PRECIS system developed by Hadley Centre

• Model has been run for A2 and B2 climate scenario for the

period of 2010 to 2050

• CO2 emission has been considered varying from year to year

according to SRES scenario

Study site

No of provinces in each group: Laos 1 (Savannakhet) – 6 Laos 2 (Vientiane) – 7 Laos 3 (Oudomxay) – 5 Thailand 1 (Ubon Ratchathani) – 2 Thailand 2 (Sakhon Nakhon) – 5 Thailand 3 (Roi Et) – 7 Thailand 4 (Nakhon Ratchasima) – 8 Cambodia (Kampong Speo) – 4 Cambodia (Battambang) – 5 Cambodia (Kratie) – 8 Cambodia (Siem Reap) – 3 Vietnam 1(Gia Lai) – 4 Vietnam 2 (Kien Giang) - 5 Vietnam 2 (Dong Thap) - 7

Model application site

Model set-up – observed vs modelled yield of rainfed rice for baseline condition, overall comparison

Modelled yield vs observed for rainfed rice

0.00 1.00 2.00 3.00 4.00 5.00 0.00 1.00 2.00 3.00 4.00 5.00 Observed average Modelled average

The model represents well the average condition for the period of 1996-2000

0.00 1.00 2.00 3.00 4.00 5.00 0.00 1.00 2.00 3.00 4.00 5.00 Observed yield, tonne/ha Modelled yield, tonne/ha

Modelled yield vs observed for irrigated rice Modelled yield vs observed for maize

0.00 1.00 2.00 3.00 4.00 5.00 0.00 1.00 2.00 3.00 4.00 5.00 Observed yield, tonne/ha Modelled yield, tonne/ha

Results – change in yield of rainfed rice

• Yield increases in A2 scenario for all sites except two
• In B2 scenario, in general yield decreases in Cambodia and Vietnam
• Yield increase is higher in A2 than that of B2
• For few location (eg. L1 and V2) yield increase in A2 and decreases in B2
• 40
• 20

20 40 L1 L2 L3 T1 T2 T3 T4 C1 C2 C3 C4 V1 V2 V3 Change from baseline, % A2 B2

Results – change in average yield of rainfed rice (up- scaling)

Change in rainfall

Change (%) of mean annual rainfall during 2010-50 relative to 1985-2000

Change in temperature

Change (°C) of mean annual daily average temperature during 2010-50 relative to 1985-2000

Impact of CO2 and temperature

• No or negligible direct impact of temperature on yield of rainfed

rice

• Increased CO2 concentration in the atmosphere help increases

yield

• 40
• 30
• 20
• 10

10 20 30 40 C1 L3 Change of yield from baseline, % A2 + Constant CO2 A2 B2 + Constant CO2 B2

Results – Irrigated rice

Percentage change from the baseline condition

0.00 2.00 4.00 6.00 Laos 1 Thailand 3 Vietnam 2 Average yield, tonne/ha Baseline A2 + Constant CO2 A2 + A2 CO2 B2 + Constant CO2 B2 + B2 CO2

• 30
• 20
• 10

10 20 30 Laos 1 Thailand 3 Vietnam 2 Change of yield from baseline, % A2 + Constant CO2 A2 + A2 CO2 B2 + Constant CO2 B2 + B2 CO2

Comparison of average yield Considered 3 sites with higher temperature and intensive irrigation Simulation was carried out considering varying CO2 and keeping CO2 at 2000 level to see impact of higher temperature only Yield increases for both A2 and B2 scenarios Yield decreases slightly if CO2 is kept at the 2000 level for future. This indicates that higher temperature slightly affect the yield adversely. The increase CO2 level in atmosphere offset the negative impact of temperature and also help increase yield

Results – Maize

Percentage change from the baseline condition Comparison of average yield Considered 8 (2 in each countries) sites in provinces with intensive maize cultivation Simulation was carried out considering varying CO2 and keeping CO2 at 2000 level to see impact of higher temperature only Yield increases for both A2 and B2 scenarios No change in yield if CO2 is kept at the 2000 level for

• future. This indicates that higher temperature does

not affect the yield adversely. The increase CO2 level in atmosphere help increase yield

0.00 2.00 4.00 6.00 8.00 Laos 2 Laos 3 Thailand 3 Thailand 4 Cambodia 2 Cambodia 3 Vietnam 1 Vietnam 3 Average yield, tonne/ha Baseline A2 + Constant CO2 A2 + A2 CO2 B2 + Constant CO2 B2 + B2 CO2

• 10

10 20 30 Laos 2 Laos 3 Thailand 3 Thailand 4 Cambodia 2 Cambodia 3 Vietnam 1 Vietnam 3 Change of yield from baseline, % A2 + Constant CO2 A2 + A2 CO2 B2 + Constant CO2 B2 + B2 CO2

Key points

• There is potential to increase yield particularly in Laos and

Thailand

• Yield would slightly decrease in Cambodia and Vietnam
• The impact of yield is mainly due to change in rainfall and CO2

concentration in the atmosphere

• There is no impact of climate change on the yield of irrigated rice if

increased irrigation requirements (11%) are met.

• There is slight direct impact of temperature increase on the yield of

irrigated rice. However, this is offset and net increase in yield is achieved due in CO2 concentration in the atmosphere.

• Yield of maize would increase all over the basin due to climate

change.

Adaptation scenarios for rainfed rice in the Mekong

• Shift planting date 2 weeks forward and 2 weeks backward from

the date considered in the baseline condition

• Reduce fertilizer stress or increase fertilizer application
• Use supplementary irrigation when necessary

Adaptation for rainfed rice – results of shift planting date

A2 B2

• Simulation was carried out for all

sites

• Yield decreases for shifting planting

date backwards in Laos, Cambodia and Vietnam but increases for Thailand for A2 scenario.

• Shifting planting date forward

increases yield in Cambodia and Vietnam, decreases in Laos and Thailand for A2 scenario. B2 scenario..

• Results are similar to that of A2

scenario except for Thailand. Yield increases for forward planting and decreases for backward planting.

• 40.0
• 30.0
• 20.0
• 10.0

0.0 10.0 20.0 30.0 40.0 L1 L2 L3 T1 T2 T3 T4 C1 C2 C3 C4 V1 V2 V3 Change from baseline, % A2B A2 A2F

• 40.0
• 30.0
• 20.0
• 10.0

0.0 10.0 20.0 30.0 40.0 L1 L2 L3 T1 T2 T3 T4 C1 C2 C3 C4 V1 V2 V3 Change from baseline, % B2B B2 B2F

Basin wide changes with adaptation of shifting the planting dates

Basin wide changes with adaptation of shifting the planting dates

Adaptation for rainfed rice – results of shift planting date, forward planting and supplementary irrigation

Scenario A2 Scenario B2

• Simulation was carried out in two

worst affected sites

• Fertilizer stress was reduced by 10%
• Supplementary irrigation was given

when necessary Results…

• Yield increases greatly for the site in

Cambodia from the baseline condition for reduced fertility stress, and supplementary irrigation.

• Highest increase can be achieved by

2 weeks forward planting and reducing the fertility stress

• In Vietnam, highest increase can be

achieved by providing supplementary irrigation

• 40
• 20

20 40 60 80 100 120 A2 A2 + 2WFP A2 + SI A2 + RFS A2 + RFS + 2WFP Adaptation strategies Change in yield from baseline (%) C1 V3

• 40
• 20

20 40 60 80 100 120 B2 B2 + 2WFP B2 + SI B2 + RFS B2 + RFS + 2WFP Adaptation strategies Change in yield from baseline (%) C1 V3

Food security

Rough rice consumption and production per capita, and country-wise current and projected average yield

Rough rice production per capita considering 2050 production and population (with adaptive planting date) (kg/capita) Projected average yield with adaptive planting date in 2050 (tonne/ha) Country Projected populatio n of 20501 (million) Rough rice consumptio n per capita (2000)2 (kg/capita) Rough rice production per capita (2000) (kg/capita) A2 B2 Average yield of rice considering total production and total harvested area in 2000 (tonne/ha) A2 B2 Average yield necessary to maintain current per capita production with no additional area (tonne/ha) Laos 9.3 254 422 286 265 3.06 3.7 3.4 5.44 Thailand 25.4 153 455 482 508 1.99 2.3 2.5 2.20 Cambodia 21.9 201 336 181 176 2.16 2.3 2.2 4.24 Vietnam 31.2 218 840 600 543 4.19 4.5 4.1 6.36 Lower Basin 87.8 192 562 428 412 2.85 3.2 3.1 4.15

Current trend suggest increase in productivity Food security (in terms of total production) and export potential is unlikely to be affected

Key points

• Over the last ten years, crop production and productivity has increased

everywhere in the basin

• The current rate of increase is considerably greater than the rate required to

feed the expected extra population by 2050

• Combined with the expected increases under climate change scenarios, it

appears unlikely that food security, in terms of the total food available, will be threatened for at least the next few decades

• However, food security for all individuals also requires that the production is

distributed equitably

• Do not consider the impact of extreme events such as floods, sea level rise,

cyclones, storm, etc. which may become more frequent with higher intensity due to climate change

• Studies show that impact of sea level rise in the deltas could have large

impacts on agriculture

DEV-A2-2048 DEV-B2-2047

Flood Area based on Maximum Flood Depth

Impacts from future climate change (CC) and development (DEV) on flood areas (%) compared to flood area in 2000

Maximum Flood Depth CC CC + DEV DEV CC CC + DEV DEV > 0.0 m +8.8 +8.2

• 0.6

+3.1 +2.5

• 0.6

> 0.5 m +13.5 +12.8

• 0.7

+3.2 +2.3

• 0.9

ECHAM4 A2 Year 2048 ECHAM4 B2 Year 2047

DEV-A2-2022 DEV-B2-2037

Saline Area based on Maximum Salinity

Impacts from future climate change (CC) and future development (DEV) on the changes of saline areas (%) compared to saline area year 1998 of baseline scenario

Maximum Saline Concentration CC CC + DEV DEV CC CC + DEV DEV ≥ 0 g/l +4.8 +0.4

• 4.3

+6.9

• 1.0
• 7.3

≥ 4 g/l +13.1

• 3.8
• 14.9

+6.6

• 1.4
• 7.5

ECHAM4 A2 Year 2022 ECHAM4 B2 Year 2037

Overall conclusion

• Estimates of impact of climate change could be biased by the

uncertainties in climate change scenarios

• Due to these uncertainties, the magnitude of impacts may be

different in different models but the trend of impacts in most cases points towards the same direction

• Need to develop new planning frameworks and methods that

will minimize the impacts and can work well across a number

• f scenarios and uncertainties
• Climate change should be in the mainstream of any National

Policy & Development Planning

• There should be greater collaboration between GO and NGO
• n collaborative research & community based adaptation

activities

Major publication

Available at: http://www.clw.csiro.au/publications/waterforahealthycountry/index.html

Water for a Healthy Country Flagship Land and Water Division

This presentation are based on projects funded by the following

• rganizations:

Australian Agency for International Development (AusAID) Water for a Healthy Country Flagship of CSIRO Mekong River Commission Mohammed Mainuddin Mohammed.Mainuddin@csiro.au

Thank you