1. Climate change
impact and
vulnerability
assessment for
agriculture
Dang Kieu Nhan
Olivier Joffre
Bun Chantrea
Jorma Koponen
ICEM – International Centre for Climate Change Impacts and Adaptation Study 1a
Environmental Management Interim Results workshop
31 October – 1 November 2012

2. Contents
1. Overview of the methodology
2. Baseline – Agriculture in the Lower Mekong Basin
3. Climate Change Impact and Vulnerability Assessment
i. Changes in Basin-wide crop suitability
ii. Vulnerability assessment for key crops in hot spots
• Champassak
• Mondulkiri
• Kien Giang
iii. Changes in Hot Spot Crop yields
4. Main Conclusions
2

3. Overview of the
methodology
3a

4. Agriculture Assessment process
MEKONG HYDROCLIMATE MODELLING & ASSESSMENT
Changes in climate Crop suitability Crop Yield
& hydrology modelling modelling
EXPOSURE X SENSITIVTY = IMPACT
X ADAPTIVE
=
VULNERABILITY
CAPACITY
Sector Key Crop Farming systems
assessment Species characterization
AGRICULTURAL SYSTEMS BASELINE
4

5. 1 Basin wide assessment approach
• Identify 8 hotspot provinces
3 representative each of the 12 ecozones
2
• Develop farming system profiles for
each ecozone
4 – Subsistence farming (small-scale)
– Commercial farming (small & large
1. Chiang Rai scale)
2. Sakon Nakhon 5 • Identify key crops for subsistence &
3. Khammouance 7 6 commercial agriculture
4. Champasak – Rice
5. Gia Lai – Cassava
6. Mondulkiri – Maize
7. Kampong Thom – Rubber
8. Kien Giang
8
– Coffee
– Sugarcane
– Soya
5

6. Agriculture
Baseline
Assessment
6a

7. Agriculture in the LMB
- Livelihoods:
- 60 million people
- 70% of population’s livelihoods rely on
agriculture
- 45% of population are considered poor
- Changes in productivity of cropping systems
will influence:
- Local livelihoods
- Rural and national economies
- Food security (national & regional)
7

8. Rapid growth in LMB agriculture
• Agriculture is a dynamic sector.
• The production of the major crops has doubled in the last 20
years, primarily due to:
• intensification of production, with higher yields rather
than larger cultivated areas.
• Some new areas for cultivation are opening in Lao PDR,
the Vietnamese Central Highlands and Cambodia
8

9. Agriculture in the LMB remains reliant on rainfall
• Key staple crops are predominately rain-fed,
• Other emerging commercial crops (maize, soya or cassava) are also mostly
rain-fed.
• LMB agriculture is highly sensitive on climate and especially on rainfall
frequency and distribution.
9
Source: MRC 2011

10. Faming systems in the LMB
Annual
1. Rice-based farming
systems
• Rainfed rice (75% of total
agricultural area)
Perennial
• Upland rainfed rice
• Lowland rainfed rice Rice
• Irrigated rice
2. Annual crops: vegetables,
maize, soya, cassava,
sugarcane, etc.
3. Perennial crops
1. Industrial crops: black
pepper, coffee, rubber, etc. 10
2. Fruits

11. LMB Farming systems
• Diverse growing conditions have led to the development of diverse farming
systems
• General historic trend towards larger farm holds and commercial farms
Rubber
Cassava
Upland Coffee
Maize
Rainfed Sugarcane
rice Lowland rainfed &
irrigated rice Soya
Fruits
Subsistence Commercial
Smallholder Historic trend Small-Large holder
Shifting Plantation
11

12. Key crop distribution in hot spot provinces
Provinces Ecozones Rice Cassava Maize Soya Sugarcane Coffee Rubber
Chiang rai High-Mid-Low, X X X X X X
Floodplains
Sakon Nakhon Mid & Low X X X X
elevation
Khammouane High & Low X X X X X
elevation
Champasak High-Low, X X X X X
Floodplains
Mondulkiri Mid & Low X X X X
elevation
Kampong Low elevation, X X X X
Thom Floodplains
Gia Lai High & Low X X X X X X
elevation
12
Kien Giang Delta swamp X X

13. Geographical distribution: Upland rice, cassava, maize
13

14. Geographical distribution: Soya, sugarcane, coffee
14

15. Baseline assessment – Summary findings
Crops Systems Locations Trends Existing Growth drivers
(area) problems
Upland rice Subsistence High-mid Increase Drought • Population growth
elevation • Urbanization (labour,
food demand, land
Lowland rice Subsistence Low Decline Drought, flood, and water use)
– commercial elevation & (Rainfed) salinity intrusion • Market demands and
delta Increase foreign investments
(irrigated) (animal feed, bio-fuel,
rubber, etc.)
Annual Subsistence High-low Changing with Drought, soil • Nation food security &
commercial - commercial elevation crops and areas erosion export policies
crops
• Natural resource
Perennial Commercial High-mid increase Drought, degradation and
industrial elevation groundwater environmental
crops depletion, soil changes
erosion
Fruits Commercial Delta Stable Flooding,

16. Basin wide Crop
suitability
assessment
16a

17. Land use suitability
• LUSET – Land use suitability evaluation tool (IRRI)
• evaluates the suitability of each land unit for a single crop
• For each location suitability is based on climatological
characteristics such as rainfall, drought and temperature
• Suitability is expressed with a scale of 0 - 100

18. Crop parameter unit
Cassava annual rainfall
drought
mm/a
months
Crop Tolerances
mean T C
mean daily max T C
Coffee annual rainfall mm/a
Robusta drought months
mean T C
mean daily max T C
av daily min T of the coldest month C
Maize growing cycle rainfall mm/cycle
first month rainfall mm/month
second month rainfall mm/month
third month rainfall mm/month
fourth month rainfall mm/month
fifth month rainfall mm/month
growing cycle T C
growing cycle mean daily min T C
rainfall in first months mm/month
Rain fed rainfall in ripening stage mm/month
rice growing cycle T C
av daily max T of the warmest month C
second month T C
av daily min T of the coldest month C
Rubber annual rainfall mm/a
drought months
mean T C
mean daily max T C
Soya growing cycle rainfall mm/cycle
first month rainfall mm/month
second month rainfall mm/month
third month rainfall mm/month
fourth month rainfall mm/month 18
growing cycle T C
growing cycle mean daily min T C

19. Crop NS S3 S2 S1 S2 S3 NS parameter weight
500 1000 1400 1800 2400 4000 annual rainfall 1
Cassava
6 Crop Tolerances
5 1 5 6 drought 2
12 18 24 29 33 45 mean T 1
16 22 29 34 38 45 mean daily max T 2
1200 1600 1800 2000 2400 3500 annual rainfall 1
3 2 1 1 2 3 drought 2
Coffee Robusta 18 20 22 30 31 32 mean T 1
22 24 27 34 35 36 mean daily max T 2
14 16 20 - - - av daily min T of the coldest month 2
300 500 600 900 1200 1600 growing cycle rainfall 2
60 75 100 220 400 475 first month rainfall 1
70 120 175 235 310 475 second month rainfall 1
70 120 175 235 310 475 third month rainfall 1
Maize
70 120 175 235 310 475 fourth month rainfall 3
60 80 100 285 400 475 fifth month rainfall 3
14 18 22 26 32 40 growing cycle T 1
7 9 12 24 28 30 growing cycle mean daily min T 2
125 175 200 300 500 650 rainfall in first months 1
50 70 150 200 500 750 rainfall in ripening stage 1
18 24 30 32 36 40 growing cycle T 1
Rain fed rice
21 26 30 40 45 50 av daily max T of the warmest month 2
18 24 26 36 42 45 second month T 1
10 14 18 22 25 30 av daily min T of the coldest month 2
1200 1500 1700 2000 2500 3000 annual rainfall 1
4 3 2 drought 2
Rubber
18 20 24 30 33 35 mean T 1
22 24 27 33 36 38 mean daily max T 2
180 350 500 1000 1600 1900 growing cycle rainfall 1
50 85 150 200 275 475 first month rainfall 1
50 80 150 200 275 475 second month rainfall 1
Soya 50 80 150 200 275 475 third month rainfall 1
40 60 85 140 275 400 fourth month rainfall 19 2
18 20 24 30 34 38 growing cycle T 1
7 9 12 24 30 31 growing cycle mean daily min T 2

20. Baseline change in 2050
Rubber
• Increase in higher
altitude areas 15% –
50% by year 2050
• Driver: higher
temperature
• Decrease in the low
altitude central area 15%
– 30% by year 2050
• Driver: increased
drought

21. Coffee Baseline change in 2050
• Increase in Northern
part 20% – 70% by
year 2050
• Driver: higher
temperature and
increased rainfall
• Decrease in
Mondulkiri 10% – 40%
by year 2050
• Driver: increased
drought, higher
temperature

22. Cassava Baseline change in 2050
• Increase in Northern
part 2% – 15% by year
2050
• Driver: higher
temperature
• Decrease in the low
altitude central area 5%
– 15% by year 2050
• Driver: increased
drought, higher
temperature

23. Soya Baseline change in 2050
• Decrease in large
areas, especially
central Laos 30% –
100% by year 2050
• Driver: increased
rainfall

24. Maize Baseline change in 2050
• Decrease in large
areas, especially
central Laos 30% –
100% by year 2050
• Driver: increased
rainfall

25. Rice 2000 change in 2050
• Increase in limited areas
5% – 10% by year 2050
• Driver: increased rainfall
in dry areas, in high
altitude areas
temperature increase
• Decrease in central Laos
5% – 20% by year 2050
• Driver: increased rainfall

26. Impact &
vulnerability
assessment for
key crop
systems
26a

27. Key climate change threats
1.Increase in temperature
2.Increase in precipitation
3.Decrease in precipitation
4.Decrease in water availability
5.Increase in water availability
6.Droughts in the rainy season
7.Flooding
8.Flash flood
9.CO2 fertilization
10.Acid rain
27

28. Assessment criteria:
Exposure Sensitivity Adaptive capacity
• Change in magnitude Physiological crop Internal factors:
of hydroclimate tolerances i.e. • biophysical factors (tolerant crops,
parameters comfort zones soil, water,…)
• Change in frequency External factors:
and duration of the • Farmer’s capacity – farming
change management and accessibility to
services
• Support systems: extension
services, infrastructure, institution,
etc
28

29. CASE STUDY OVERVIEW
CHAMPASSAK PROVINCE
29

30. Current farming systems
• Largest land holdings in Lao PDR
(2.1ha/HH) with rice as main crop
– >70% lowland rainfed rice cultivated
during the wet season
– <20%farmers cultivate both in dry and
wet season.
• Lowland rice supplemented with
90
additional rainfed crops for subsistence
(chilli, banana, sweet potato, beans 60
Area (103 ha)
etc...) 30
• Small holder coffee is dominant in the
0
Bolovens plateau
Coffee
Rainfed
Rubber
Cassava
Maize
Irrigated
Soya
rice
• Cassava culture is booming, based on
rice
smallholder and contract farming
30
• Rubber concessions cover large areas

31. Key climate change threats for Robusta coffee
Climate Change Sensitivity
Threats
Increased High temperature (> 32oC) in the dry season affects coffee growth and
temperature production
Optimal water supply is 1750 mm/year, with high suitability ranging from
Increased rainfall
1600 to 2400 mm and a dry period for flower initiation in March-April
Decreased rainfall Decreased precipitation during dry season causes water stress.
Drought Long dry spells (> 20 days) can affect the production due to water stress
Heavy rains (> 250 mm/day) in upland and/or upstreams create a sudden
Flash floods water level rise (rivers, stream) and carries debris, damaging coffee
plant/production.
Storms Coffee can suffer from strong winds and flash flood generated by storms.
Increase of CO2 might have an impact on growth and water use efficiency
CO2 increase
Acid rains can affect coffee production in the long term with damaged
Acid rains leaves and reduced photosynthesis
31

32. Effects of increased temperature on coffee
Threat: High temperature (> 32oC) in the dry season affects coffee
growth and production
Exposure: Very high
• 80% of days with Ave. Max. temp. > 32ºC in Jan – Nov,
• 20% of days with extreme max. temp > 36ºC in Jan – Oct.
Sensitivity: Medium
High dry season temperatures can increase evapotranspiration and increased water
stress
Impact: High
Reduced productivity
Adaptive Capacity: Medium
-Internal capacity: Medium
-External capacity: High; shade-management practice
32
Vulnerability Score: Very High

33. Champassak Summary
Vulnerability Assessment
Projected changes in temperature 2050
40% increase in
proportion of dry
season >32 C
33

34. Champassak - Summary of vulnerability for key crops
CC threat Irrigated Lowland maize Cassava Rubber coffee
rice rainfed rice
Increased
High High Medium Medium Medium Very High
temperature
Increased
Low Medium High High Low High
rainfall
Decreased
Medium Medium Low Medium
rainfall
Droughts Low Low Low Medium Medium
Flooding Low Medium Medium Medium
Flash floods Medium Low Medium Medium Medium Medium
Storms Low Medium Medium High Medium High
CO2 increase Medium Medium Medium High Medium Medium
Acid Rain Low Medium

35. CASE STUDY OVERVIEW
MONDOLKIRI PROVINCE
35a

36. Current farming systems
- Forested area dominates
agricultural land
- The subsistence system is based
on rainfed rice and “chamkcar”
system, with vegetable and other
crops such as maize, soya,
cassava, tarot, sweet potato and 20
mungbeans.
Area (103 ha)
- Emerging commercial/industrial 10
crops:
- Rubber 0
Rainfed
Cashew
Cassava
Rubber
Soya
- Cashew
rice
- Banana
36

37. Key climate change threats for rainfed rice
Threats Sensitivity
Increased Optimal range is 24-36ºC, above 36ºC at flowering and milking stages inducing
temperature sterility and a lower number of filled grains
Increase in Increased rainfall might benefit the rice. However, rice suffers with excessive rains,
rainfall inducing submergence at early stages, sterility and lodging at later stages, reducing
potential yield. Upper rainfall limit is about 600 mm/month for the 1st month and for
the last month.
Decreased Decrease in soil water availability can generate stress and affect yield, particularly in
water avail. early and late rainy periods.
Increased Rice is tolerant to anoxia and an increase in soil water availability and so this
water avail. change will not be a threat but benefit.
Drought Dry spell in the rainy season causes water stress =>reduce rice yields. At the
flowering stage, rice can suffer a severe yield loss with a 8-12 -day drought.
Flooding Flooding in the wet season can damage rice crop but floodplain area in the province
is limited
Storms Storms with strong wind and heavy rains cause submergence and hence reduces rice
37
yields, particularly at the flowering and harvesting time (Nov-Dec).
CO2 increase Increase in atm CO2 level might promote rice growth and hence increasing yields

38. Effect of increased rainfall on rainfed rice
Threat/opportunity: rice production benefits, or suffers from, an increase in
rainfall ?
38
Source: ICEM (2012)

39. Effect of increased rainfall on rainfed rice
Threat/opportunity: rice production benefits by, or suffers from, an increase
in rainfall ?
Exposure: low (negative/positive)
• An increase in rainfall will supply more water and reduce water stress for the rice crop in May-
Jul. However, excessive rainfall in Oct (25% probability), rice not flowering yet, might cause
submergence.
Sensitivity: Low (negative/positive)
• An increase in rainfall in May-Sep and Nov is still in comfort zone. The rice crop has low
sensitivity to the excessive amount of rainfall in Oct, which is less likely to cause
submergence.
Impact: Low (negative/positive)
• Rice crop will best respond to increased rainfall in May-Sep and in Nov. Increased rains in
Oct will have low negative impacts.
Adaptive Capacity: High
• Internal capacity: high – traditional rice more tolerant to submergence
• External capacity: medium – farmers can apply adaptive farming practices to take use of
higher rainfall at early stages and mitigate impacts of heavy rains at later stages. 39
Vulnerability Score: Low (negative/positive)

40. Summary of vulnerability assessment for key crops - Mondolkiri
Climate change Rainfed rice Rubber Cassava Soya
Increased temp Medium Medium Medium High
Increased rainfall Low Low Medium Medium
Decreased water avail. Medium Medium Low High
Increased water avail. Very Low Medium Low Low
Drought Medium Medium Very Low Medium
Flooding Medium Medium Medium Medium
Storms Medium Low Low Medium
CO2 atm. Increase Medium Medium Medium Medium
40

41. CASE STUDY OVERVIEW
KIEN GIANG PROVINCE
41

42. Current farming systems
-Fresh water area:
• Alluvial soils with irrigation systems
• 2-3 rice crops/year
• Rotational rice – vegetable farming
-Saline water and acidic area:
• Salinity intrusion (dry season)
• Rice - shrimp rotation
• Secondary crops: Area (103ha) 300
• Sugarcane 200
• pineapple. 100
0
Sugarcanne
Rainfed rice
Irrigated
rice

43. Key climate change threats for rainfed rice – Kien Giang
Climate Change Sensitivity
Threats
Increased Optimal range is 24-36ºC, above 36ºC at flowering and milking stages
temperature inducing sterility and a lower number of filled grain
Increased rainfall Heavy rains in Sep – Nov causes submergence, sterility and lodging at
flowering-ripening stages
Decreased Decreased rainfall in Jul-Sep constrains washing soil salinity and hence
rainfall damaging young rice plant
Drought Dry spell in early and late rainy season affect yield, with combined effects of
salinity intrusion and acidification
Flood Flood is associated heavy rains, causing submergence Sep – Nov.
Storm Storms with strong wind and heavy rains affect rice yields , particularly at the
flowering, milking and ripening stages.
Sea level rise Rice can be damaged by saline water (≥ 4‰) intrusion, particularly in early
(SLR) and later stage of rice crop.
Increased salinity Most of current rice varieties cannot tolerate to a salinity level above 4‰,
particularly at young, panicle initiation and flowering stages.

44. 500 25
Rainfall
400 20
Monthly rainfall (mm)
Canal water salinity (‰)
Salinity at location
300 15 far from estuary
salinity at location
close to estuary
200 10
100 5
0 0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Rice Rice Rice Rice - Rice
Shrimp Seedling Rice Rice -Shrimp
Shrimp Shrimp mono-culture

45. 9
Tolerant: Y = 5.1 - 0.2X - 0.02X 2
8 2
Less tolerant: Y = 5.3 - 0.9X + 0.05X
7 Sensitive: Y = 5.0 - 1.4X + 0.1X 2
Tolerant
Yields (tons ha -1)
6 Less tolerant
Sensitive
5
4
3
2
1
0
0 1 2 3 4 5 6 7
Salinity (‰)

46. Vulnerability of rice to sea level rise (SLR & salinity increase)
Threat: SLR increases salinity intrusion, shortens freshwater duration for rice,
damages rice crops and reduces rice culture area.
Sensitivity: Very high
• Rice can suffer from a salinity level above 2‰ in a prolonged period. Above 2‰,
rice yield reduces by 0.2-1.5 tons/ha with every unit (1‰) increase
Impact: Very high
• Rice crop suffers a significant loss (1-4 tons/ha) with a prolonged period of a
salinity level up to 4‰
Adaptive Capacity: High
• Medium internal capacity – tolerant rice varieties and other farming practices can
stand for a salinity level up to 4‰
• High external capacity: good current salinity management structure; with good
extension and institutional supports, farmers can shift to saline aquaculture
Vulnerability Score: High 46

47. Champassak Summary
Vulnerability Assessment
Summary of vulnerability assessment for key crops
Rainfed rice Irrigated rice
Increased temperature Medium Medium
Increased rainfall Medium Medium
Decreased rainfall Medium Medium
Drought Medium Medium
Flood Medium Medium
Storm Medium Medium
Sea level rise (SLR) High Medium-High
Increased salinity High Medium-High 47

48. Summary of VA for key crops: high vulnerability
Provinces Rainfed rice Irrigated rice Cassava Maize Soya Sugar- Coffee Rubber
cane
Chiang Rai High High Medium Medium Medium
(temp) (lower water)
Sakon High High Medium High
Nakhon (temp) (rain, flood) (temp)
Kham- High Medium High High High Medium
mouane (temp) (rain) (rain, (rain, storm)
storm)
Cham High High High High High Medium
-pasak (temp, storm) (temp) (rain) (rain) (temp, rain,
storm)
Mondulkiri High High High Medium
(temp) (flash flood) (temp)
Kongpong High High High High Medium
Thom (temp, lower (temp, lower (flood) (temp, lower
water) water) water)
Gia Lai High High High High Medium High Medium
(temp) (temp) (flood, flash (storm, (temp)
flood) flash flood)
Kien Giang High Medium-High
(SLR, (SLR, salinity)
salinity)

49. Hotspot crop
yield
assessment
49a

50. Crop yield
• Crop yield is computed with the physiological FAO AquaCrop
model
• AquaCrop is integrated with the hydrological model
yield
Establishment | Vegetative | Flowering | Formation | Ripening | Maturity
Reduction in max
canopy cover
Decline in
canopy cover
during
productive
phases (yield
formation/
ripening)
Delay in time to reach max canopy cover
Source: FAO, 2010

51. Rain fed rice yield
Baseline Change in 2050
• Increase in Eastern
Khorat Plateau 5%
– 20% by year 2050
• Driver: increased
rainfall

52. Average annual yields in the
selected provinces

53. Conclusions
53a

54. • Impacts of the projected changes in the climatic parameters differ:
• among crops in the same hot spot
• among hot spot with the same crop
• Robusta coffee and cassava:
• Become more suitable in northern parts with an increase in
temperature
• Suffer from droughts and a decrease in water availability in central
parts
• Cassava, soya and maize: less suitable with an increase in rainfall in
the wet season
54

55. • Both rainfed and irrigated rice are highly vulnerable to:
• increased temperature in the wet season
• decreased water availability in the dry season
• salinity intrusion (in the delta)
• Coffee is highly vulnerable to increased temperature in the dry
season
• Rubber and sugarcane are relatively robust crops to changes in
climatic parameters
• Effect of increased rainfall in the wet season on rainfed rice:
• small negative impact in “wet” areas like Champasak, Gia Lai.
• possitive impacts in a “dry” area like Sakon Nakhon.
55