The Niger Basin is a large transboundary basin spanning 10 countries in West Africa. It experiences highly variable rainfall and widespread poverty. Population growth is expected to be extreme, putting additional pressure on water resources. While irrigation development has potential to increase food security and livelihoods, most agriculture is currently rainfed and vulnerable to climate fluctuations. Improving water productivity in both rainfed and irrigated systems through better management practices could help optimize utilization of the Niger Basin's water resources under changing conditions.
1. Niger Basin Focal Project
Coordination:
Chiang Mai workshop, 18 September 2009
Jean Charles CLANET
Andrew OGILVIE
2. Large transboundary basin
• 4183 km
• 2.1 M km² / 1.2 M km²
• 10 countries
Country Basin size per country Proportion Proportion
(km ²) of basin of country
w ithin w ithin
country basin (% )
(% )
Benin 44,967 3,5 38,7
Burkina Faso 86,919 6,8 31,5
Cameroon 86,381 6,8 18,4
Côte d’Ivoire 23,550 1,9 7,3
Guinea 98,095 7,7 39,9
Mali 263,168 20,7 20,9
Niger 87,846 6,9 7,4
Nigeria 562,372 44,2 61,5
Tchad 19,516 1,5 1,5
TO L Active
TA 1,272,814 100 -
Basin
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
3. Spanning range of agroclimatic zones
From <50mm in North to >4500mm in South
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
4. Prone to extreme demographic expansion
Evolution of Niger Basin population 2005-2050 according to various UN DESA scenarios
450 000 000
400 000 000 384 036 651
350 000 000 Constant-fertility variant
High variant
Medium variant
300 000 000
Low variant
246 388 996
Population
250 000 000
215 273 326
200 000 000
186 656 464
150 000 000
100 000 000
94 506 856
50 000 000
-
2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Year
Population density
(Source: D Kaczan based on SEDAC data)
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
5. Due to high fertility
• Future population trends will
depend on speed of fertility
decrease and HIV/AIDS
prevalence
Sources: Tabutin and Guengan
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
6. Subject to extreme poverty
• 8 in Low development category
UNDP HDI
• Generalised poverty where
education, roads, electricity,
health, water sector are
underdeveloped
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
7. Often regarded as water poor
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
9. WP2: Rainfall distribution
300
300 700
730
520
200 450 Mean annual rainfall (average 1951-1990),
200
100 and monthly rainfall for wet and dry years
100
0
0 J M M J S
400 J M M J S
1700
300
300 1350 1050
30 0 900
200 1200 200
20 0 1100
100
100
0 10 0
J M M J S 0
0 J M M J S
J M M J S
• Uneven water distribution
– Significant rainfall in South and up to 13° N
– Quarter of basin under Sahel and Semi-arid climate
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
10. Rainfall variability
• Seasonal and inter-
annual variations
• Recent drought and
future uncertainties
Cartographie SIG, C. Dieulin, 2009, IRD/ HSM
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
11. Impact on river flows
• Peculiar hydrology
• 3 major « châteaux
d’eau » in South of
basin
Source: Marquette, Zwarts et al, FAO
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
12. Advances in basin hydrology
Main Niger sub-basins and annual hydrographs
for wet and dry years • Ability to
predict
Discharges in m3/s
changes in
flow from
B C rainfall
predictions
• Impact of
A D dams,
E climate
change,
F land use
change etc
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
13. Hydrogeology…
• Large uncertainties
over GW reserves
• 5-50 mm/year GW
recharge depending
on location and land
use
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
14. Towards water accounting
Gretp1984.shp
0
0 - 17422
17422 - 21228
21228 - 25547
25547 - 31439
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
15. Water use: green water
• Substantial rainfall
(except North)
• But short and erratic
rainy season
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
16. WP3: Blue water use and irrigation
• Blue water largely
under-exploited
• Irrigation largely
under-developed
• Reliance on rainfed
agriculture
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
17. Irrigation zones and systems
• Irrigation along river • Small dams
• Inner Delta • Recession flood
• Nigeria dams, fadamas, • Lowlands
Sokoto
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
18. Nigeria’s greater control over water
• Nigeria as leader in
dam construction
and irrigation
types de périmètres Burkina Mali Niger Nigeria total
grands périmètres 8000 62500 13000 69 000 152500
PIV publique 3000 9500 12500
PIV collectif 6000 8000 14000
PIV individuel 4000 50000 161 700 215700
petit privé 30000 30000
agroindust 4000 4500 8500
décrue 60000 12000 723 000 795 000
submers cont 85000 85 000
basfonds subm cont 9000 22000 18 500 49 500
total 34000 281500 75000 972 500 390500
Source (Association Régionale de l'Irrigation et du Drainage en Afrique de l'Ouest et du Centre 2004)
FAO 1992 et JICA 1993 pour le Nigéria
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
19. Vast potential for irrigation
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
20. WPr of selected irrigation zones
Superficie
Nom des Pluviométrie Superficie intensité
Typologie APPIA Pays fleuves Date de réalisation moyenne par Culture principale
périmètres moyenne annuelle équipée(en ha) culturale %
exploitant (ha)
Lata T1 Niger 756 1991 227,0 1,00 Riz 200
Kamaka T2 Mali 451 1994 16,0 0,41 Riz
Sinah T2 Mali 449 1997 49,0 1,00 Riz 100
Saba 1 T3 Mali 410 2001 35,0 2,50 Riz 100
B1 T1 Mali 383 1951 576,7 20,00 Riz 151
Djidian T1 Mali 553 1950 298,0 12,00 Riz 100
Boundoum T1 Sénégal 250 1991 262,0 1,70 Riz
Nakambe/ bagre T1 Burkina Faso 910 1974 680,0 1,00 Riz 200
Vallée du Kou T1 Burkina Faso 943 1970 1260,0 1,00 Riz 200
Sakoira T3 Niger 379 1992 3,6
WPr of market gardening activitivies and rice
0,20 Oignon 180
Source: APPIA
Tera T2 Niger 382 1981 46,0 1,00 oignon, tomate 125
Gamkale T4 Niger 526 1980 200,0 0,16 choux, poivron, laitue 200
Mbida T2 Niger 334 1997 17,0 0,07 Niébé 200
Keur Mbir Ndao T4 Sénégal 326 1966 20,0 0,08 Oignon
Mbawane T4 Sénégal 366 1974 40,0 1,20 Oignon
pomme de terre,
Titao Burkina Faso 588 1999 4,5 0,06
T3 oignon 200
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
21. WPr in wet and dry season
Wet season Dry season
3000.0 2000.0
Gross Inflow (mm/ha) I rrigation (mm/ha)
Evapot ranspirat ion (mm/ha) 1800.0
2500.0 Ev apotranspiration (mm/ha)
1600.0
1400.0
2000.0
1200.0
1500.0 1000.0
800.0
1000.0
600.0
400.0
500.0
200.0
0.0 0.0
Bargodaga Kamaka Sinah Saba1 Djidian B1 N10 Lata B1 N10 Sakoira Tera Gamkale Mbida
Irrigation Scheme Irrigation Scheme
25000 Irrigated inflow (m3) 1.00 35000.0 6.0
Irrigation inflow (mm/ha)
Yield (Kg)
WP (Kg/m3) 0.90 Gross Value Product ($/ha)
Gross Valur Product/ Irrigation inflow
30000.0
WP ($/m3)
5.0
20000 0.80
W ate r Productivity (kg/m 3)
Water productivity ($/m3)
25000.0
0.70
4.0
15000 0.60
20000.0
Yie ld (kg)
0.50 3.0
15000.0
10000 0.40
2.0
0.30 10000.0
5000 0.20
1.0
5000.0
0.10
0 0.00 0.0 0.0
Kamaka B1 Sinah Djidian N10 Saba1 Bargodaga Lata B1 N10 Sakoira Tera Gamkale Mbida
Irrigation Schemes Irrigation Scheme
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
24. Rainfed Water productivity
1999, good year
kg grain per ton applied water: Intercepted rainfall
kg grain per ton depleted water:
Evapotranspirable water
• Maps of rainfed WPr
Leached soils
Heavy rainfall
according to CPWF definition
Rainfed cereals = marginal crops • Difficult/dangerous to
Major crops = lowland rice
interpret
=> return to theory
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
25. Increasing rain utility
• Within context of increasing strain on water resources need to ensure water is used
efficiently and to produce most value (food, energy, water supply, environment)
strive to increase total utility of water (increase/better water depending activities, save
water and assign it to activities showing a deficit). In agriculture, “more crop per drop”
• Rainfed agriculture differs somewhat as rain is not necessarily the limiting factor, even in
Sahel (Breman and Cissoko, 1998)
• Rainfed agriculture also faces two constraints:
– cannot reduce applied water (the rainfall is an environmental data );
– cannot try to reduce depleted water (actual ET is an environmental function which
controls the moisture and rain parameters (Monteny and Casenave, 1989)
• To increase the direct utility of the rain one can only improve the rainfed production process
– where rain falls in excess, reduce its noxiousness;
– where it falls insufficiently, improve its efficiency (RUE);
– if rain is adequate, reduce the other limiting factors
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
26. Measuring direct utility of rain
• Rain is a necessary condition to rainfed production but not necessarily a (limiting) factor
• WProd does not inform the level of utility of rain in general, and must be reserved for
activities where water is really a factor (such as irrigation, or rainfed in arid zone).
• In rainfed agriculture, this rain utility can be measured in various indicators:
– Average yield : productivity of the “rain field” (= land) assigned to rainfed crop
– Average food production per rural capita (allows to judge satisfaction of the needs,
and labour productivity)
– Population living of rain resources (human production of the " rain field")
– Land use assigned to the rainfed crops
•very low rainfed land
use in Guinea and arid
zone (<5%) rainfed =
marginal activity
• relatively low global
rainfed land-use (<15%)
• some districts in
Niger, and Nigeria >25%
– Rain-use efficiency (RUE) when the rain is a limiting factor
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
27. Rain as a limiting factor
max. phytomass (t MS/ha)
12
Savanna grass production becomes 10
dependent to variations in rainfall 8 perennial grass, slope, latitude
11-12°N
above 10°N (below 800mm) 6
perennial grass, slope, latitude
4
(Fournier 1991). 6-9°N
2
0
400 600 800 1000 1200 1400 1600
rainfall of the year (mm)
t de céréales par habitant rural (Cereal ton/capita)
Usual droughts (1986): 0,50
1984 1986 1988 1994
no effect if zone >800mm 0,45
small effect 500-800mm 0,40
great effect <500mm 0,35
= (insufficiency) 0,30
0,25
0,20
FS
Heavy droughts (1984) 0,15
great effect <1000mm 0,10
(insufficiency) 0,05
-
sahélien<500 soudanosahel nord soud centre sud
500-600mm 600-800 soudanien soudanien
800-1000 >1000 mm
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
28. RUE when rain is limiting factor
• Relevant in areas of rainfall under 600mm for pearl millet, 700 mm for sorghum (at the
beginning of cycle), 800 m for maize, 900 mm for tubers, 1000 mm for rice (approximately).
• How to measure it?
Actual ET is not an universal water index, as dependent on ETP and ETM Prod/ETa is not
relevant RUE index
RUE index: water satisfaction index: actual ET/potentiel ET or a better water indicator
(IRESP). The higher the water index, the higher the yield
RUE index: relative yield (actual yield/potential yield) at a standard deficit (IRESP 0,5 or
actET/potET 0,75)
• Increase RUE by
1) increasing water
Relative yield satisfaction index (= reduce
1 deficit = synchronising offer
and demand)
System B System A
2) increasing relative yield in
case of water index <1, and
reducing drought resistance
0 Water index
IRESP 0,5 1
(minimising actual ET of zero
IRESP, yield)
0
ActualET/potential ET
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
30. Inner Delta fisheries
Delta amont (Juilet à octobre 1995)
Surface 15000
inondée
2
(km ) 0,0093x
10000 y = 36,637e
2
R = 0,9629
5000
0
0 200 400 600 800
Hauteur d'eau à la station de Mopti (cm)
100 Total catch
(tonsx1000)
80
60
40
20
0
500 1000 1500 2000 2500
Inflow Mopti (m3/s, July-November)
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
31. Marginal WPr in Inner Delta fisheries
Fish marketed in Mopti ( t; t+1) according to flood index (t)
25000
y = 157.47x - 483
20000 R2 = 0.72
15000
10000
5000
0
20 40 60 80 100 120 140
Flood index (in days)
Abstraction of some volume to the river flood decreases the fish catch,
about 28 tonnes/y for 1 m3/s during the flood period.
Data for 1988-2005 from Mali administration, processed by CP 72
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
32. Constraints to livelihood in fisheries
socio economic environment of poor countries
(school, health, domestic water, credit)
poor productive assets
sometimes a lack of landuse rights
environmental change
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
33. Fisheries in the Niger basin
• Major drivers of change:
– changes in hydrologic regime
• rainfall variability and climate change,
• construction of reservoirs and water abstraction
– increased pressure on ressource,
• increased total population and boom on fish demand by
urban markets,
• increased fishers population
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
35. Livestock Water Productivity
• LWP= ∑ Value of production and services (V)
Quantity of water withdrawn for production and services
LWP= Vv + Vl + Vf + Vt + Vcp
Qefn + Qefc + Qerr + Qecm
Animal products and services: meat (v), milk (l), manure (f), traction
and transport (t), leather & skin (cp)
Water in animal feed (natural, fn; cultivated; fc); crop residues (rr),
drinking water (cm)
• Data gathering complete for V, finalising calculations for
water from animal feed and crop residues (Crop water use)
• Continue determining options to improve systems and LWP
where necessary (questions over how to interpret LWP)
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
37. Evolution of stock numbers 1978-2050
Evolution annuelle du cheptel (bovins et petits ruminants) en zone agroclimatique
aride du système pastoral du BFN de 1978 à 2008
450000
400000
350000
300000
Nombre (Tête)
250000
200000
150000
100000
50000
0
Année
Bovins Petits Ruminants
Evolution annuelle du cheptel (bovins, petits ruminants et camelins) en zone
agroclimatique aride du système pastoral du BFN de 2008 à 2050
18000000
16000000
14000000
12000000
Nombre (Tête)
10000000
8000000
6000000
4000000
2000000
0
Année
Bovins Petits Ruminants Camelins
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
38. Pastoral & trade movements
Clanet, 2009
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
39. Leglislation surrounding pastoralism
DISPOSITIFS Benin Burkina Cam. Côte Iv Guinée Mali Niger Nigeria2 Tchad
Locaux (us et coutumes) X X X X X X X X X
Nationaux (Législatifs : textes, lois codes, X X X X X X X X X
décrets, schémas directeurs … 1987 1984 1983 1982 1995 1996 1997 1979 1960
Gestion quotidienne L>N L>N L>N L>N L>N L>N L>N L>N L>N
Bassin - - - - - - - X -
Régionaux
•CEDEAO
(x) x x x X X X
•CEBV
x x x x x x -
•CILSS
x x x x x x x - x
Dispositifs focalises sur : Migrants Aména- N.r. Aména- Prati- Code Aména- Sectoriel Hydrau
gements gements ques A-P gements lique
1- PRASET : Projet Régional d'Appui au Secteur de l'Elevage Transhumant, GTZ, Niamey, 1997
2- Hors CEDEO
3- CEDAO : Communauté des Etats de l’Afrique de l’Ouest
4- CILSS : Comité inter-états de lutte contre la sécheresse au Sahel
5- CEBV : Communauté du bétail et de la Viande
Mobilités pastorales transfrontalières besoin: « sécuriser le foncier pastoral » (PRASET, Niamey,
GTZ, 1997).
Legislation exists but rarely applied. Local customs take precedence over national law
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
40. WP4: Institutional context
• Transboundary dependance
• Lack of transboundary and
national water management
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
41. Institutional difficulties
Bénin BF Cam C.I. Gui Mali Niger Nigeria Tchad
Droit/Politi Permis Droits
que Concession Titre foncier ationaliste Propriété Propriété Propriété Pas clair
d’occuper occupation
GIRE Projet PAGIRE Gire = Cellule GIRE
Principes
adopté Plan directeur Pris en compte À améliorer Principe
pilote reconnus défi
Décentralis
ation Inachevé,
6 dép. 13 régions 10 provinces début Collectivités 8 régions 789 LGAs Difficile
déficit
Gouv/Cout Reconnaiss Reconnaiss Reconnaiss Reconnaiss Reconnaiss
umier ance Chefs consultés À améliorer ance ance ance Pas reconnu Très mauvais ance
Genre PDFA PDFA - - PDFA PDFA - PDFA -
signé signé signé signé signé
• Recent
institutions/decentralisation
• Budding IWRM
• Uneven recognition of
traditional law
D’après 2iE, EIER-ETSHER
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
42. Importance of institutions at local level
• Impact on WPr
via land tenure
• Existing systems
based on
traditional
law/customs
Users type Proprietor Claimant Authorized User Authorized Entrant
- State
- ‘Maître des eaux, des terres, des pâturages’ Exploitation unity (e.g. with
Lineage member: Undifferentiated actor :
Property right in the Inner discretionary power on water, land or pasture fishery right)
prescribed right for individual or herd
Delta access or outsider (with a temporal
pasture access without particular status
- Chiefs (village, family, lineage or production right for extraction)
unit)
Access X X X X
Withdrawal X X X
Management X X
Exclusion X
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
43. Legal pluralism issue
- Legal plurality: overlap of traditional
and modern water/land rights
- Decentralisation, IWRM, NGOs add to
this plurality
- Creates more authority structures
& levels and set of rules
- Case by case study required, some
mixtures work better than others
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
44. WP1: Water and poverty at a national scale
Falkenmark WPI
HDI -0.21 n/a
SVI 0.07 -0.47
GSI -0.18 -0.08
Headcount
Ratio 0.26 -0.34
CSIRO.
45. Issue no. 1: What and where is poverty?
Child mortality
Child morbidity universally agreed-to metric
No Hot spot
(stunting)
Household
wealth
CSIRO.
46. Issue no. 2: Accounting for causes of
poverty
•Derive weightings from the data
• Spatially explicit modelling – heterogeneous coefficients for a
heterogeneous problem
CSIRO.
47. Outcomes: e.g. Central Mali
For each hotspot, we identified the most serious water constraint
• Water poverty manifests in different ways in different places
Central Mali and the Inner Delta
Poverty definitions are
crucial → use multiple
metrics simultaneously
and compare results
CSIRO.
49. Outcomes: Considerable variation between hotspots
Considerable disparity between results analysed for child
mortality and child stunting – warrants using multiple
metrics
• All findings based on statistical correlations, not observed causality
North West Nigeria:
• Water quality (access to protected sources) is the primary water-
related poverty correlate. 1% improvement is associated with a 1.1%
decrease in child mort. rates
• Secondary evidence: Irrigation has been beneficial as well as water
access
• Education: 1yr improvement in average schooling attainment is
associated with a 0.6% decrease in child mort. rates.
CSIRO.
50. Outcomes: variation between hotspots
Utility of the
Poverty Water poverty Non-water TARWR
Hotspot Measure of poverty variables poverty variables variable
Water access
Moderate –
North west Unprotected water Education
All three metrics child mortality
Nigeria Irrigation Livestock
only
TARWR
Central Mali
Education Limited – not
and the Inner Child mort. only Unprotected water
Livestock significant
Delta
Limited – child
East Burkina Unprotected water Education
All three metrics morbidity only,
Faso Dams Environ. damage
contrary signs
Education
Population
East Nigeria and Limited – child
Irrigation density
north Wealth index only mortality only,
Dams Malaria
Cameroon contrary signs
Drought risk
Environ. damage
South and Access to towns
Limited –
central Nigeria Education
All three metrics Unprotected water contrary signs,
(‘wealth Electricity
CSIRO. small effect
hotspot’) Telephones
52. AgWat & poverty
• Sample agricultural problems:
– access to water
– poor soil fertility
– pests
– crop diseases
– lack of inputs
– access to markets
• Improvements needed in:
– Awareness raising, information
and communication
– Training and capacity building
– Equipment
– Legal and administrative
frameworks
– Finances
– Cooperation and information
exchange
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
53. Physical interventions
Source: UNESCO
Adapt demand to water supply Conservation tillage and conservation agriculture
(photosensitivity, better decision making currently not possible in semi-arid conditions of
for sowing, extensivity), West and Center Africa (very strong competition
with other crop residues uses)
Adapt supply to crop demand (runoff control Intensification does not enhance RUE, except
and water harvesting, rooting) through organic matter inputs.
Enhancing tolerance to supply-demand gap in Supplemental irrigation during short dry-spells and
deficit (rooting management, drought beginnings of humid seas in intensive farming
resistance) or excess (drainage tolerancy) only
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
54. SENEGAL à BAKEL 16.74
8 9 10 11 12 13 14 1 I22 3 4 5
J2
6 7
Flow predictions
13.95
22
MAN TALI
23
AN
24 25 26 27
NIGER à 15 ULIKOURO 18
28
KO 16 17 19 20 21
11.16
SE G E
LIN U
36 37 38 39 40 41 42 29 30 31 32 33 34 35
latitude
8.37
50 51 52 53 54
FOMI 55 56 43 44 45
H5
46 47 48 49
² 5.58
• Predictions in August for Sept-Oct rainfall used 64
78
65
79
66
80
67
81
68
82
69
83
G5
70
84
57
71
58
72
59
73
60
74
61
75
62
76
63
77
2.79
to predict flow data 92 93 94 95 96
0
97 98
500
85
1000 km
86 87 88 89 90 91
0
-2.79
• Used for Manantali dam in Senegal. Extension to -21.09 -18.28 -15.47 -12.66 -9.84 -7.03 -4.22 -1.40
longitude
1.41 4.22 7.04 9.85 12.66 15.47
Niger river upstream of Inner Delta Figure 1 : Location of Bakel in Senegal basin and
Koulikouro in Niger and zones used for predictions in
• Spatiotemportal uncertainty for rainfall the Arpege model
predictions (7 days feasible)
3000 3000 3000 m3/s
fleuve SENEGAL à Bakel
m3/s calage m3/s calage calage
2500 2500 2500
2000 2000 2000
1500 1500 1500
1000 1000 1000
500 prévu = f ( J2 ) 500 prévu = f ( G5 ) 500 prévu = f ( H5 )
observé année observé observé
année prévu en temps réel
année
0 prévu en temps réel 0 prévu en temps réel 0
1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010
fleuve NIGER à Koulikouro
5000 calage 5000
m3/s calage
m3/s
4000 4000
3000 3000
2000 2000
1000 prévu = f ( G5 ) 1000 prévu = f ( I2 )
observé année observé année
0 0 prévu en temps réel
1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010
Modèle : ARPEGE 3 forcé Modèle : ARPEGE 4.6 forcé Modèle : ARPEGE 4.5 couplé
Figure 2 : results for natural river flow in sept-oct at Bakel in Senegal river basin and Koulikoro in Niger river basin, obtained from the
successive versions of ARPEGE
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
56. Climate change modelling
• High uncertainty
• Increase in T°C,
in variability and
extreme events,
later start of
rainy season,
HADCM2 – A2 scenario Variability of discharges for some basins near 2080 in regard dry spells, and
of the average 1966-1995
overall more
rain in Central
part of WA &
decrease in
West
• Variation in
yields
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
57. Water development and IWRM
• Dam building
– Impact on local
people
– Impact d/s
– Against scientific
advice
BFP NIGER Niger
Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
58. Initial conclusions
• Water and poverty: complex relation, yet to be proved…
• Large potential for WPr improvements but above 800mm
rainfall, water rarely a limiting factor. Under 800mm rainfall,
water is only one variable. Others more significant
• Difficult to implement (weak economy, reliance on aid, diversity
of ethnicities/languages, insecurity).
• Improvements in water management need to be accompanied
by institutional and cultural changes to support them. Also
investment, markets, microfinance… Easier to import cheap
products than invest in national agriculture?
• Large potential for irrigation (x 000s ha), rainfed agriculture,
livestock, integrated systems (fisheries, agroforestry)
• Large scale hydraulic investment – complicate situation not
opposite…
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
59. Further insights
• Wider causes of poverty need to be addressed
– Eg. impacts of improvements in education
• Literacy improvements should also alleviate demographic
pressure and future water « stress »
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU
60. Thank you for your attention
BFP NIGER Coordination: Jean Charles CLANET & Andrew OGILVIE – IRD/G-EAU