The Iullemeden Aquifer System (IAS) underlying parts of Mali, Niger, and Nigeria is facing several risks to its groundwater resources. These risks include increasing water demand from population growth, weak management of the transboundary aquifer, effects of climate change like decreasing rainfall, and a reduction in groundwater recharge rates due to issues like deforestation, erosion, and river siltation. The IAS is also threatened by water quality impacts from pollution and naturally occurring fluoride. The MSP-GEF project aims to address these risks through activities like developing a common database, mathematical models, and a mechanism for joint groundwater management between the three countries.

1. MSP-GEF project
Managing Hydrogeological Risks in
the Iullemeden Aquifer System IAS
(Mali, Niger, Nigeria)
GEF Third Biennial International Waters Conference
Brazil, 20-25 june, 2005
A. Dodo

2. Situation of IAS in the Niger river basin
Niger Superior
(257 000 km²)
Delta Interior
(85.000 Km²)
Niger Middle
(660 000 km² ) :
Niger Inferior
(650 000
km²) :

3. Niger
Nigeria
Mali
R. Niger
Overview of the Iullemeden Aquifer System
•Mali, Niger, Nigeria
•525 000 km²
•Mali : 31000 km² (6%)
•Niger : 434000 km² (83%)
•Nigeria : 60000 km² (11%).
Aquifers:
•Cretaceaous
Continental intercalaire
•Tertiary Continental
Terminal

4. The Iullemeden Aquifer System is subjected
to several real and/or potential risks :
 The increase of the water demand because of the growth of the
population : 15 millions in 2000, the double in 2025;
 A Weak sudden Basin Awareness : groundwater shared;
 The Climatic changes;
 The mitigation of groundwater recharge rate (because of deforestation: in
Niger : weak productivity of the forests (0,1 to 1,5 stere/ha/year)
against 87% of the energizing needs between 1,5 and 2 millions
tons of firewood per year. In Mali: 90% of the needs of firewood) ;
 The silting of the rivers (deforestation, erosion);
 The deterioration of water quality because of:
 The pollutions: domestic, industrial, mining, artisanal, agricultural;
 The groundwater geochemistry of the Continental intercalaire
(attendance of Apatite): Bony Fluoroseses.

5. Basin Awareness : Transboundary Shared
Water Resources Management

6. Climatic Changes : Annual isoyietal map (mm) in the Sahel
part of the SAI: Sliding of isoyietes southwards of about 100
km: decrease of 20% to 30% of the rainfall

7. Mitigation of surface
run-off : 20 to 50% to the
detriment of the Ecosystem
Mitigation of Niger river
run-off at Koulikoro: 23 %
Evolution des Modules du Niger à KOULIKORO de
1950 à 2002
2500
2000
1500
1000
500
0
Moy.Mobile sur 5 ans
1950
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
Evolution des Débits annuels : Ecart à la Moyenne
600
500
400
300
200
100
0
-100
-200
-300
-400
-500
1950
1954
1958
1962
1966
1970
1974
1978
1982
1986
1990
1994
1998
2002
Ecart (m3/s)
Ecart / Moyenne (864 m3/s)
Mitigation of Niger river
run-off at Niamey : 36,2%

8. Mitigation of Groundwater Recharge rate :
Dégradation of land forest for firewood
Installation of sand
Erosion and silting in Niger river
dunes

9. Consequences of deforestation, silting : Subsidence of the
groundwater table that sustains very weakly or not the run-off
4,00
3,00
2,00
1,00
0,00
-1,00
-2,00
-3,00
-4,00
● Niger superior in Mali (Pilot experience in152 500 Km²)
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
3
2
1
0
-1
-2
-3
-4
Ecr (Pluie)
Ecr (Débit)
Cumul Ecr.-Piézo.
(R. Dessouassi et G. Mahé , 1997)

10. Artisanal Pollution : Tannery, Dyeing

11. Excess of Fluoride (6 mg/l) in Continental intercalaire Aquifer
Bony Fluoroseses
Apatite :
Ca5(PO4)3 (OH, F, Cl)
More than 300 victims
mainly children
irreparably deformed

12. MSP-GEF project gives a good opportunities
- A state of knowledge ooff wwaatteerr rreessoouurrcceess uuppddaatteedd iinn
tthhee hhoollee BBaassiinn;;
-- AA CCoommmmoonn DDaattaa bbaassee ttoo tthhee 33 ccoouunnttrriieess;;
-- AA MMaatthheemmaattiiccaall MMooddeellss ffoorr tthhee eessttaabblliisshhmmeenntt ooff aa
hhyyddrrooggeeoollooggiiccaall rriisskkss mmaapp aanndd ffoorr ssuussttaaiinnaabbllee wwaatteerr
rreessoouurrcceess mmaannaaggeemmeenntt;;
-- AAnn iinniittiiaattiioonn ttoo tthhee MMeecchhaanniissmm ooff CCoonncceerrttaattiioonn ffoorr tthhee
jjooiinntt ggrroouunnddwwaatteerr rreessoouurrcceess mmaannaaggeemmeenntt aanndd ffoorr tthhee
mmoonniittoorriinngg ooff tthhee rreelleevvaanntt iinnddiiccaattoorrss ooff
hhyyddrrooggeeoollooggiiccaall rriisskkss

13. TThhaannkk YYoouu