6 CONCLUSION AND RECOMMENDATIONS
The project to fight against Zio river silting up and erosion
in the basin requires a perfect knowledge of the zone and its state of
degradation so to identify suitable measurements of fight. Those are concerned
which made object of this study resulting from its work arrived at the
conclusions and recommendations hereafter:
- From the geological and geomorphologic point of
view, basin of Zio is cutting in a sedimentary material sandy and clay
with low water holding capacity; which justifies the fast infiltration of the
an important volume rainwater to be collected towards the principal flow;
- River silting up and erosion, in the basin are
the major problems of degradation due to the combined effects of the factors
natural and human of destruction of the environment;
- Zio river in the coastal sedimentary basin
runs, in a channel of relatively weak unevenness whose value of the
slopes does not exceed 2%; what facilitates the deposit of loads during the
falls and low water levels contributing to the stranding of the river bed;
- Degradation of the basin forestry cover, has
naked the grounds is the principal cause of erosion.
To protect Zio river banks and fight against erosion in the
basin, the study recommends the participative and sustainable reforestation
with the idea to promote the agroforestry and to manage the bush fires
effectively, to protect the biodiversity, to limit eutrophication, to sensitize
the bordering populations, to control soil erosion and put anti-erosive
measurements into practice.
Although efforts are in hand on the various sectors level
concerned with management studied zone to constitute a data base, there is a
crucial lack reliable and recent data on sedimentary basin coast. This
situation does not encourage initiative to undertake studies on the area. Thus,
it pressing for the ministries concerned regarding question to create
harmonized data base on the sedimentary basin coast and with need together for
all territory with for coordinator the Ministry of Environment and Forestry
Resources.
We are convinced if all these measurements taken into account
and implementations, it obvious that very soon the environment of a favorable
environment for the bordering populations will reappear in the basin.
To finish, we launch a call to all those which work for
fundamental research in connection with river basins, in particular those of
the coastal sedimentary basin of Togo, to take account of the well-elaborated
intentions in the various work studies. It through this frank scientific
collaboration, the spirit of interdisciplinary can really contribute to the
human and sustainable development of our country.
REFERENCES
ADDRA, H (1975): Erosion régressive au quaternaire
récent et modèle du plateau de terre de barre (exemple du plateau
de Vogan), Ann, Univ du Bénin, série Lettres Tome 2,
no 2 Lomé, pp 30-49.
AKIBODE, A. S. Nelson (2000): Contribution a l'Etude Hydro
geomorphologique de la Basse vallée du Zio, Memo, Univ du Benin, Lome,
75 p
ANONYME (1981): Périmètre irrigué du Zio,
étude socio-économique, Rapport SOTED, Direction du Plan,
Lomé, 48 p.
BLIVI, A (1993): Géomorphologie et dynamique actuelle du
littoral du Togo (Afrique de l'Ouest), Thèse de Doctorat, Bordeaux, 458
p.
CHURCH, H et MOSS, R. P (1980): West Africa, a study of the
environment of man's use of it, Londres, 526 p
COLOMBANY, J (1968): Notice hydrologique sur le Bassin du Zio
à Kpédji, ORSTOM, Lomé, 42 p.
COUDRAY, J et BOUGUERA, M. L (1994): Environnement en milieu
tropical, ESTEM, Paris, 19 p.
GNONGBO, T. Y (1989): Contribution à l'étude
géomorphologique de la basse vallée du Zio, Mém, Univ. Du
Bénin, Lomé, 124 p.
GU-KONU, Y et al (1981): Atlas du Togo, J.A, Paris, 64 p.
HERVIEU, J (1968): Contribution à l'étude de
l'alluvionnement en milieu tropical, Mém, ORSTOM, n0 24, Paris, 58 p.
IROKO, O. Yao (2006): Fondements pour l'Elaboration du
Schéma Directeur de l'Aménagement Environnemental de la
Région des Plateaux, Mém, InSTEC, La Havane/Cuba,
JOHNSON, K (1987): Le Bassin côtier à phosphates du
Togo, Thèse, Univ. de Bourgogne- Dijon, 248 p.
KLASSOU, K. S (1989): Impact du climat sur l'évolution du
régime hydrologique, le cas du Zio et du Haho, Mém, Univ du
Bénin, Lomé, 120 p.
Martin, P. Wanielista (1990): Hydrology and Water Quantity
Control, Univ. New York, USA MICHEL, P (1990): Géographie physique
tropicale (Approche aux études du milieu), Karthala-ACCT, Paris, 351
p.
NORMAN, C (1982): Pluies de grains, pluies de mousson et
environnement dans la zone maritime du Togo, Mém, Univ. du Bénin,
Lomé, 122 p.
PECH, P et REGNAULD, H (1992): Géographie physique PUF,
Paris, 315 p.
PIERRE, G (1974): Dictionnaire de la Géographie PUF,
Paris, 346 p.
RYDING, S.O. and RAST, W. (1989): The Control of Eutrophication
of Lakes and Reservoirs, MAB (UNESCO) Vol. 1, Paris, 314 p.
SLANSKY, M (1962): Contribution à l'étude
géologique du bassin sédimentaire du Dahomey et du Togo,
Mém du BRGM, no11, Paris, 270 p.
SOGBEDJI, M (1987): Etude de la pluviométrie au Togo
Méridional, Rapport ORSTOM, Lomé, 24 p.
TIMO PUKKALA and KALLE EERIKAINEN (1998): Modelling the growth
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34 p.
CHARTS AND FLY PHOTOS DOCUMENTS USED
- Togo topographic charts/ 1/50 000 IGN, Paris, 1954,
covering study zone:
1.
|
Kouété
|
Feuille NB-3 1 -XIX-2b
|
2.
|
Kati
|
Feuille NB-3 1 -XIII-4d
|
3.
|
Palimé
|
Feuille NB-3 1 -XIV-4b
|
4.
|
Lomé 3a
|
Feuille NB-31-XIV-3a
|
5.
|
Lomé 1c
|
Feuille NB-31-XIV-1c
|
6.
|
Lomé 1d
|
Feuille NB-31-XIV-1d
|
7.
|
|
Lomé 1b
|
Feuille NB-31-XIV-1b
|
|
- Fly photography/ 1/30 000, Maritime Region covering
study zone:
1.
|
Vol. 77-TOG-31/300:
|
2475
|
- 2476
|
- 2477
|
- 2478
|
- 2479
|
- 2480
|
|
|
2491
|
- 2492
|
- 2493
|
- 2494
|
- 2495
|
- 2496
|
2.
|
Vol. 78-TOG-31/300:
|
3368
|
- 3369
|
- 3370
|
- 3371
|
- 3372
|
- 3373
|
3.
|
Vol. 79-TOG-31/300:
|
3584
|
- 3385
|
- 3586
|
- 3587
|
- 3588
|
- 3589
|
TABLE OF FIGURES
1. Study area chart localization and geology
2. Curves of the monthly average temperatures of the basin over
25 years
3. Rainfall graphs of the monthly averages of the basin over 30
years
4. Curves of evolution of the monthly averages of sunstroke and
evaporation in the basin
5. Water supply of the Zio river
6. Zio catchments area and hydrographic network
7. Curves of evolution of annual average precipitations over 20
years
8. Curves of annual medium flows of Zio over 21 years period
9. Curves of evolution of Zio flowing over 21 years
10. Zio alluvia terraces space provision
11. Recognizing Zio valley geomorphology sketch in coastal
sedimentary basin (Akibodé, 2000)
12. Zio basin topographic sketches indicating the silting up
level
13. Zio basin tenure (Akibodé, 2000)
14. Indicators chart of Zio basin environmental degradation
(Akibodé, 2000)
Sources:
TOGO:
. Ministère de l'Environnement et des
Ressources Forestières
. Départements de Géographie, de
Géologie/Université de Lomé
. Direction de l'Urbanisme et du Cadastre
. Ministère de l'Agriculture, de
l'Elevage et de la Pêche
. Ministère des Mines, Energie et
Eau
. Riverains et autres usagers du basin
GERMANY:
. Technische Universität Dresden -
Library/Dresden
. Institute of Soil Science and Site
Ecology/TUD/Tharandt
. Ministry for the Environment, Nature
Conservation and Nuclear Safety, Berlin . Centre for
International Postgraduate Studies of Environmental Management (CIPSEM)/TUD
. Neunzehnhain Ecological Station: Training and
research Center of Water Engineering Department of the Faculty of Forestry,
Geo- and Hydrosciences TUD
. The International Academy for Nature
Conservation, Isle of Vilm . German National Park
. Regional Commis sion/Council Integrated Rhine
Programme, Freiburg
Others:
. Czech Republic: Institute of System Biology
and Ecology, Academy of Sciences of the Czech Republic, Ceske Budejovice &
Prague
. France: National School for Water and
Environment Engineering, Strasbourg (Research Centre in Agricultural and
Environmental Engineering)
| 
