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Do recent West African rainfall variations really impact the livestock in the Sahel?

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(1)

Do recent West African rainfall

variations really impact the livestock

in the Sahel?

Pierre OZER

Department of Environmental Sciences and Management

University of Liege, Arlon, Belgium

pozer@ulg.ac.be

be.troplive Symposium, Brussels, 14 November 2013

(2)

Sahel : Senegal, Mauritania, Mali, Burkina Faso, Niger

150 mm 700 mm

Hyper-arid:

Desert

Arid/Semiarid:

Sahel

Dry subhumid:

Soudanese

(3)

Ozer et al, in press

250 350 450 550 650 750 1921 1931 1941 1951 1961 1971 1981 1991 2001 P lu v io m étr ie a n n u el le (m m ) . Pluviométrie annuelle Moyenne centrée [9 ans] Moyenne 1921-1967 Moyenne 1968-2004 Moyenne 1968-1987 Moyenne 1994-2004

(4)
(5)

Spatial extent of the rainfall shortages of the 1970’s and 1980’s

in Niger

(6)

Spatial extent of recent rainfall changes in the Sahel

(1950-2007)

(7)

JOURS DE PLUIE

-3,0% / 10 ans (**)

20

30

40

50

60

1940

1950

1960

1970

1980

1990

2000

Années

J

o

u

rs

.

BUT: Number of rainfall days in Niger (1940-2003)

(8)

JOURS DE PLUIE > 99e PERCENTILE

+36,6% / 10 ans (*)

0

1

2

3

4

1940

1950

1960

1970

1980

1990

2000

Années

J

o

u

rs

.

BUT: Number of extreme rainfall days in Niamey (1940-2003)

(9)

JOURS DE PLUIE > 99e PERCENTILE

+36,6% / 10 ans (*)

0

1

2

3

4

1940

1950

1960

1970

1980

1990

2000

Années

J

o

u

rs

.

BUT: Number of extreme rainfall days in Niamey (1940-2003)

Very likely a result of

climate change

(10)

BUT: Rainfall trends in Niger

(11)

BUT: NDVI trends in Niger

(12)

BUT: Rainfall Use Efficiency (RUE) trends in Niger

(13)

Hountondji, Sokpon, Ozer, 2006

(14)

What’s next ? End of 21st century compared to 1980-1999

(15)

What’s next ? End of 21st century compared to 1980-1999

(16)

What’s next ?

(17)

What’s next ?

(18)

We have (likely, 66% to 90% of chance) a serious problem

0

20

40

60

80

100

120

140

160

180

200

1960

1970

1980

1990

2000

2010

2020

2030

2040

2050

P

o

p

u

la

tio

n

(m

illio

n

s)

Human population in the Sahel

Population

Projections

1960-2012: +3.1%/yr

2013-2050: +2.1%/yr

17

30

67

180

Data: FAO, 2013

(19)

0

5

10

15

20

25

30

35

1961

1968

1975

1982

1989

1996

2003

2010

He

ads

(mill

ion

)

Sahel - Cattle (heads)

The livestock in the Sahel ?

(20)

-15

-10

-5

0

5

10

15

1961

1968

1975

1982

1989

1996

2003

2010

%

Cattle - year to year % evolution in the Sahel

The livestock in the Sahel ?

(21)
(22)

UNIVERSITE DE LIEGE 2010 22

Eastern Niger, ~300-400 mm

(23)

The livestock in the Sahel ?

(24)

Is this correct ?

(25)

Is this correct ?

(26)

Niger: drought of 2005

« the effect of the severe drought on the livestock has

been devastating »

(27)

Niger: drought of 2005

« the effect of the severe drought on the livestock has

been devastating »

(28)

Niger: drought of 2005

« the effect of the severe drought on the livestock has

been devastating »

Niger:

Cattle in 2005 vs 2004:

+ 6 % (406,250 heads)

(29)

Niger:

drought

(30)

Niger:

drought

(31)

Niger: drought of 2010

« The drought threatens almost 70 % of herds (Red Cross) »

« It could take up to 10 years to rebuild the losses in livestock.

Next year, people will not be able to survive off their livestock

(Niger Association for the Revival of Breeding) »

(32)

Niger: drought of 2010

« The drought threatens almost 70 % of herds (Red Cross) »

« It could take up to 10 years to rebuild the losses in livestock.

Next year, people will not be able to survive off their livestock

(Niger Association for the Revival of Breeding) »

Niger:

Cattle in 2010 vs 2009:

+ 6 % (555,698 heads)

(33)

Is this correct ?

(34)

Is this correct ?

(35)

Is this correct ?

(36)

References

FAO, 2013. FAOSTAT, FAO Statistical Databases. http://faostat.fao.org/ , last access: November 14, 2013.

Held, IM, Delworth, TL, Lu, J, Findell, KL, & Knutson, TR. (2005). Simulation of Sahel drought in the 20th and 21st centuries.

PNAS, 102, 17891-17896.

Hountondji, Y, Nicolas, J, Sokpon, N, & Ozer, P. (2005). Mise en évidence de la résilience de la végétation sahélienne par télédétection basse résolution au Niger à la suite d’épisodes de sécheresse. Belgeo, 2005(4), 499-516.

http://hdl.handle.net/2268/18895

Hountondji, Y, Sokpon, N, & Ozer, P. (2006). Analysis of the vegetation trends using low resolution remote sensing data in Burkina Faso (1982-1999) for the monitoring of desertification. International Journal of Remote Sensing, 27(5-6), 871-884.

http://hdl.handle.net/2268/15720

IPCC (2007). Climate change 2007: synthesis report. In: Contribution of Working Groups I, II and III To the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, K. Pachauri and A. Reisinger, Eds., IPCC, Geneva, Switzerland. Lebel, T, & Ali, A. (2009). Recent trends in the Central and Western Sahel rainfall regime (1990–2007). Journal of Hydrology,

375, 52-64.

Ozer, P, & Erpicum, M. (1995). Méthodologie pour une meilleure représentation spatio-temporelle des fluctuations pluviométriques observées au Niger depuis 1905. Sciences et changements planétaires / Sécheresse, 6(1), 103-108.

http://hdl.handle.net/2268/16544

Ozer, A, & Ozer, P. (2005). Désertification au Sahel : Crise climatique ou anthropique ? Bulletin des Séances de l’Académie

Royale des Sciences d’Outre-Mer = Mededelingen der Zittingen van de Koninklijke Academie voor Overzeese Wetenschappen, 51(4), 395-423. http://hdl.handle.net/2268/16053

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