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Effect of Rainfall and flood on rice production in Bangladesh Jun MATSUMOTO (Department of Geography, Tokyo Metropolitan Univ., JAMSTEC/DCOPand Haruhisa ASADA (Nara Women’s Univ.) International Conference on Climate Change Innovation and Resilience for Sustainable Livelihood 12-14 January 2015, Kathmandu, Nepal

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Effect of Rainfall and flood on

rice production in Bangladesh

Jun MATSUMOTO (Department of Geography,

Tokyo Metropolitan Univ., JAMSTEC/DCOP)

and Haruhisa ASADA (Nara Women’s Univ.)

International Conference on Climate Change Innovation

and Resilience for Sustainable Livelihood

12-14 January 2015, Kathmandu, Nepal

Foodgrain production (in rainy season) and Monsoon

Rainfall in India: 1966-1988. (Parthasarathy et al. 1992)

In India, rice production depends

greatly on summer monsoon

rainfall. Significant positive

correlation (r = 0.878) exists

between foodgrain production

and summer monsoon rainfall

(Jun.-Sep.) in the whole country.

Introduction

Wet year → Good harvest

Dry year → Poor harvest

Although regional differences are

expected, little has been known.

→ Need to reveal the past and

present linkage between climate

parameters, farmer’s responses

and rice production in regional

level before considering future

climate change adaptation.

Relationship between year to year changes of rice

production and summer monsoon rainfall in India (left)

and in Thailand (right) (Gadgil and Rupa Kumar, 2006)

Purpose: How about the situation

in Bangladesh?

Data used in the study

3. Agricultural Data (1947-2010)

Rice production (t), area (ha), yield (t/ha)

and irrigated area (ha) of local variety and HYV.

Source: Yearbook of Agricultural Statistics, BBS

2. Flood Data (1954-2010)

1. Rainfall Data (1980-2010)

Flood affected area (percentage of country total area).

Source: Bangladesh Water Development Board (BWDB)

Monsoon rainfall (total amount of 34 stations during June-September)

Source: Bangladesh Meteorological Department (BMD)

-20

-15

-10

-5

0

5

10

15

20

25

30000

35000

40000

45000

50000

55000

60000

65000

70000

75000

198

0198

1198

2198

3198

4198

5198

6198

7198

8198

9199

0199

1199

2199

3199

4199

51

99

6199

7199

81

99

9200

0200

12

00

2200

3200

4200

5200

6200

7200

8200

9201

0

Year

to Y

ear

change o

f A

man y

ield

Monsoon r

ain

fall

Monsoon rainfall - Aman rice yield (% change) during 1980-2010

Monsoon rainfall

Aman rice yield (%)

(mm) (%)

Year to year changes of rice production, and summer

monsoon rainfall in Bangladesh

R² = 0.1227

-25

-20

-15

-10

-5

0

5

10

15

20

25

-40 -30 -20 -10 0 10 20 30 40

Year to year change of Monsoon rainfall

Monsoon rainfall - Aman rice yield (% change) during 1980-2010

(%)

(%) Year to year change of Aman yield

Relationship between year to year changes of rice

production and summer monsoon rainfall in Bangladesh

Flood inundation map

of Bangladesh in 1998

(Area of total

inundation is 68%)

Flood inundation map

of Bangladesh in 2004

(Area of total

inundation is 38%)

Flood inundation map

of Bangladesh in 2007

(Area of total

inundation is 32%)

Rice cropping patterns in Bangladesh

Aman: Wet

season rice

Boro: Dry

season rice

Figure 1. The inter-annual variation of the rice production

and flood affected area from 1947 to 2010.

0

5

10

15

20

25

30

35

0

10

20

30

40

50

60

70

80

90

100

194

7194

9195

1195

3195

5195

7195

9196

1196

3196

5196

7196

9197

1197

3197

5197

7197

9198

1198

3198

5198

7198

9199

1199

3199

5199

7199

9200

1200

3200

5200

7200

9

Pro

duct

ion

(106

ton)

Flo

od a

ffect

ed a

rea

(%)

Flood affected area (%) Aus

Aman Boro

Total rice

Figure 2. The inter-annual variation of the rice cultivated area

and flood affected area from 1947 to 2010

0

2

4

6

8

10

12

14

0

10

20

30

40

50

60

70

80

90

100

194

7194

9195

1195

3195

5195

7195

9196

1196

3196

5196

7196

9197

1197

3197

5197

7197

9198

1198

3198

5198

7198

9199

11

99

3199

5199

7199

9200

1200

3200

5200

7200

9

Cul

tivat

ed a

rea

(106

ha)

Flo

od a

ffect

ed a

rea

(%)

Flood affected area (%) Aus

Aman Boro

Total rice

Figure 3. The inter-annual variation of the rice

yield and flood affected area from 1947 to 2010.

0

0.5

1

1.5

2

2.5

3

3.5

4

0

10

20

30

40

50

60

70

80

90

100

194

7194

9195

1195

3195

5195

7195

9196

1196

3196

5196

71

96

9197

1197

3197

5197

7197

9198

1198

3198

5198

7198

9199

1199

31

99

5199

7199

9200

1200

3200

5200

7200

9

Yie

ld (

ton/

ha)

Flo

od a

ffect

ed a

rea

(%)

Flood affected area(%)

Aus

Aman

Boro

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0

10

20

30

40

50

60

70

80

90

100

196

9

197

1

197

3

197

5

197

7

197

9

198

1

198

3

198

5

19

87

198

9

199

1

199

3

199

5

19

97

199

9

200

1

200

3

200

5

200

7

200

9

Cul

tivat

ed a

nd ir

rigat

ed a

reas

(10

6 ha

)

Flo

od a

ffect

ed a

rea

(%)

Flood affected area(%)

Local Boro

HYV Boro

Irrigated area

Figure 4. Variations of Boro rice, cultivated area, irrigated area

and flood affected area (1969-2010)

Summary (1)

• Year-to year variations of rice production were poorly

correlated with those of summer monsoon rainfall in

Bangladesh where water from outside is more important

and interesting features associated with severe floods

were found.

• Amon rice production in the severe flood years was

decreased due to the decrease of cultivation area. In the

following dry season, boro rice production was increased

due to the increase of cultivation area. The following wet

season, both aman and boro rice productions were

increased due to the increase of both yield and

cultivation area resulting in the great increase of total rice

productions in the following severe flood years.

Summary (2)

• After severe flood in 1998, rice production in dry

season exceeds that in wet season in Bangladesh,

and it is now becoming the major rice due to the

increase of irrigation. As such Bangladesh rice

cultivation has been developed stepwise to overcome

severe flood damages.

• The results seem to show strong resilience or

effective adaptation strategy of rice production to the

recent frequent flood damages in Bangladesh.

• Floods are not harmful for Bangladesh agriculture in a

long-term perspective?

References

•Asada, H., J. Matsumoto, and R. Rahman. (2005). “Impact

of recent severe floods on rice production in Bangladesh.”

Geographical Review of Japan, 78 (12): 783–793.

•Asada, H. and J. Matsumoto. (2009). “Effects of rainfall

variation on rice production in the Ganges-Brahmaputra

basin.” Climate Research, 38 (3): 249–260.

•Asada, H. (2012). Climate and Rice Cropping Systems in

the Brahmaputra Basin: An Approach to Area Studies on

Bangladesh and Assam. Rubi Enterprise, Dhaka, 115pp.