Assessing rice cultivation's sustainability through an examination of extreme rainfall events using the Markov Chain approach

1. Assessing rice cultivation's sustainability
through an examination of extreme
rainfall events using the Markov Chain
approach
Masoud Barati
03/17/2022
Amrita School for Sustainable Development
Thematic Area: SDG Indicator 2.4.1-Sustainable Agriculture
1

2. 2
Current status of Rice Production

3. 3
NRRI Research Bulletin No. 22
Perspectives

4. 4
Rice Yield and Area harvested in India
https://www.fao.org

5. We can no longer rely on traditional
farming knowledge and practices
 Rice grows in different climatic conditions, However
it displays high drought sensitivity and is highly
vulnerable to climate change (Duhan & Pandey,
2013; Mandal et al., 2013). Climate change (changes
in rainfall patterns) is expected to variously affect
rice productivity and yields, a 30 to 35% and upto
80% rice yield reduction by 2050 and 2080 was
projected, respectively (Geethalakshmi and
Dheebakaran, 2008).
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6. 6
Making rice climate-proof

7. Water requirements in lowland rice
Total season : 675-4450 mm
Typical value : 1500 mm
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8. District Season Sowing time Harvesting time Duration (Days)
Sadivayal
Kar
(SWM)
May – Jun
(20th to 28th SMW)
Aug – Sep
(35th to 39th SMW)
< 120
Thaladi
(NEM)
Sep – Oct
(38th to 42nd SMW)
Jan – Feb
(47th to 4th SMW)
130 – 135
The sowing and harvesting period of rice growing seasons
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Standard Meteorological Week (SMW)
South-West Monsoon (SWM)
North-East Monsoon (NEM)

9. 9
Rice growth stages

10. 10
Rice water and inputs requirement in growth stages

11. 11
Markov Chain Process
rain no rain
0.6
0.4 0.8
0.2
Stochastic Transition diagram:
Markov Property: The state of the system at time t+1
depends only on the state of the system at time t









8
.
0
2
.
0
6
.
0
4
.
0
P
• Stochastic matrix:
Rows sum up to 1
• Double stochastic matrix:
Rows and columns sum up to 1
The transition matrix:
Weather:
• raining today 40% rain tomorrow
60% no rain tomorrow
• not raining today 20% rain tomorrow
80% no rain tomorrow
   
x
| X
x
X
x
x
X
| X
x
X t
t
t
t
t
t
t
t 



 


 1
1
1
1
1
1 Pr
Pr 

X1 X2 X3 X4 X5
•Two states : ‘Rain’ and ‘Dry’.
• Transition probabilities: P(‘Rain’|‘Rain’)=0.4 , P(‘Dry’|‘Rain’)=0.2 ,
P(‘Rain’|‘Dry’)=0.6, P(‘Dry’|‘Dry’)=0.8
• Initial probabilities: say P(‘Rain’)=0.4 , P(‘Dry’)=0.6 .

12. Probability distribution for describing
weekly rainfall
 Using incomplete gamma probability distribution, weekly rainfall for different return
periods as well as percent probability of occurrence of desire amount of rainfall was
estimated.
 A random variable x is said to have a gamma probability distribution with parameter
and β if its probability density function is equal to zero given by the following equation:
 In this distribution, α and β are known as the shape and scale parameters,
respectively, and Γ (α) is the gamma function. Maximum likelihood estimation
technique was employed for obtaining the estimates of α and β.
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13. Initial, Conditional Probability of
occurrence of dry and wet spells
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A) Kar Growing Season B) Thaladi Growing Season

14. Initial, Conditional Probability of
occurrence of dry and wet spells
14
A) Kar Growing Season B) Thaladi Growing Season

15. 15
Probability of consecutive of
wet and dry weeks
A) Kar Growing Season B) Thaladi Growing Season

16. 16
Probability of consecutive of
wet and dry weeks
A) Kar Growing Season B) Thaladi Growing Season

17. Weekly-assured rainfall amount (mm) at different probability levels (10-90%)
A) Kar Growing Season B) Thaladi Groing Season
Probability distribution for weekly rainfall
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18. Weekly-assured rainfall amount (mm) at different probability levels (10-90%)
A) Kar Growing Season B) Thaladi Groing Season
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Probability distribution for weekly rainfall

19. 19
Proposed Mitigation and Adaptation strategies for
rainfed rice cultivation in Kar Growing Season
Seedling Vegetative
Conclusion

20. 20
Proposed Mitigation and Adaptation strategies for
rainfed rice cultivation in Thaladi Growing Season
Conclusion
Seedling Vegetative Reproductive Ripening

21. References
• H Pathak, R Tripathi, NN Jambhulkar, JP Bisen and BB Panda (2020). Eco-regional Rice Farming for Enhancing
Productivity, Profitability and Sustainability. NRRI Research Bulletin No. 22, ICAR-National Rice Research Institute,
Cuttack 753006, Odisha, India. pp 28.
• Pathak H, Nayak AK, Jena M, Singh ON, Samal P and Sharma SG (Eds.) (2018) Rice Research for Enhancing
Productivity, Profitability and Climate Resilience, ICAR-National Rice Research Institute, Cuttack, Odisha, p
527 + xv, ISBN: 81- 88409-04-09
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