First International Conference on MOLDAVIAN RISKS – FROM ...

<strong>First</strong> <strong>International</strong> <strong>Conference</strong> on MOLDAVIAN RISKS - FROM GLOBAL TO LOCAL SCALE
16-19 May 2012, Bacau, Romania
INFLUENCE OF LAND USES ON WATER FLOW AND
NUTRIENTS IN THE WATERSHED TAABO: INTEREST OF A
MODELING WITH SWAT
Armand Anoh Kouao 1, 2 , Jean Patrice Jourda 2 , Kan Jean Kouame 2 ,
Tanoh Jean-Jacques Koua 1,2 , Gabriel Lazar 1
1 "Vasile Alecsandri" University of Bacau, Environment and Mechanical Engineering Dept.
Romania
2 University of Cocody-Abidjan, Laboratory for Remote Sensing and Spatial Analysis
Applied to Hydrogeology, Cote d’Ivoire
Corresponding author: anohkouaoarmand@yahoo.fr /anohkoua@gmail.com
Abstract: In Cote d’Ivoire, as in most developing countries, the combination of poverty
and population growth in the watershed contribute with many problems in terms of natural
resource degradation, such as soil, forests and water. The river system in Cote d’Ivoire has
four major basins, including Bandama wich represents 32% of the total reservoir of the
country. Created in 1975, Lake Watershed Taabo (sub Bandama basin) has made available
to Ivorians and rural people in particular, a vast expanse of water to multiple uses. The
core activity of most indigenous peoples remains agriculture which occupies almost 85%
of land in the basin. Moreover, since lake creation, the forest cover has been reduced from
78% to 25% in early 1990. This reduction in forest area favored by the agriculture
intensification increased tenfold the leaching phenomena and soil erosion. However,
leaching and soil erosion associated with increasing fertilizer inputs result in losses of
nutriments to the river system resulting eutrophication problems experienced by 26% of
the total area of the lake since 1990s. University studies conducted on the Taabo retention
in 2002 and 2007 show that it is attacked by many anthropogenic activities of local
residents. It also present at level of physical-chemical characteristics, an overall annual
input and output flows of suspended solids of approximately 8812 tons or 16% of
particulate flows. Therefore, the protection of this water is imperative because of its
susceptibility to exploitation and pollution. Unfortunately, in Cote d’Ivoire, no surface
water has benefit yet of an environmental protection program. It would therefore be
advisable that sustainable management of water resources is integrated into development
of Cote d’Ivoire for an economic and social development in the long term. A palliative
solution for water pollution will be agro-hydrological modeling with SWAT model to
reflect the complexity of the interactions between climate, soils and plants. The purpose of
this study is to evaluate the feasibility of an agro-hydrological modeling of the Taabo
watershed, to quantify the phenomena of diffuse pollution, appreciate their origins, and
suggest priority areas for action for actions restoration of the water quality.
Keywords: Hydrologie, nutrient, eutrophication, river basin management, Modeling, SWAT.
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