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Kouame K.F.,Center University Of Recherche Et Dapplication En Tele Detection Curat | Lasm T.,University Of Cocody | Dreuzy J.R.D.,University of Rennes 1 | Akafou A.G.,University Of Cocody | And 2 more authors.
Revue des Sciences de l'Eau | Year: 2010

The modelling of groundwater flow in a fractured network was carried out using a theoretical approach based on the geometric characteristics of the fractures in the Achaean basement of the Touba region (Ivory Coast). This study is based on structural data (fracture network) interpreted from satellite imagery, and confirmed by field surveys. The characterization of the geometric parameters (study of scale laws) and the study of network connectivity were followed by calculations of flows and equivalent induced permeability using a discrete fractures model based on several hypotheses (e.g., only fractures and fault zones are conducting and permeable; all the fractures are vertical and have the same permeability; the hydraulic gradient is applied on a square domain independent of the topography). The Touba region fractures network is a mature (fracture length distribution follows a power law) and fractal (self-similar) network. The simulated flows are strongly channelled in fractures of regional size which largely control the connectivity of the network under the above assumptions regarding the physiographic characteristics of the area and the imposed hydraulic gradient. The groundwater pathways, determined by the hydrogeologic model, seem to agree with the zones of mean and high yield. In central and western Touba, the model produced satisfactory results (partial conformability between the simulated groundwater pathways and boreholes that have mean and high yields). This result is promising with respect to the identification of the best sites for drilling high yield boreholes.

Toure B.,University of Fribourg | Kouame K.F.,Center University Of Recherche Et Dapplication En Tele Detection Curat | Souleye W.,University Cheik Anta Diop Of Dakar | Collet C.,University of Fribourg | And 4 more authors.
Geomorphologie: Relief, Processus, Environnement | Year: 2012

The erosion affecting the coast of Port-Bouet (Abidjan, Ivory Coast) is a major threat and concern to the economic infrastructure of the Ivorian Refining Company (SIR), the Felix Houphouet Boigny airport international and homes along the coast. In recent years, in order to better understand this scientific accumulation-erosion budget phenomenon, CURAT (Centre Universitaire de Recherche et d'Application en Tiliditection) undertook studies both in situ and from a mapping approach to assess the rate of coastal retreat on the sandy coasts of the Ivory Coast. In this study, the study changes in the morphology of the coastal area of Abidjan, the economic capital of Cote d'lvoire, was derived from the use of the software Digital Shoreline Analysis System (DSAS) to process vertical aerial photographs, and Corona and HRG panchromatic SPOTS imagery to estimate the displacement of shorelines by photointerpretation. The mid-secular evolution of the coastline (beach dune contact) has been analysed over 42 years (1967-2009). We discuss the role of the destabilising developments and crises on the erosive dynamics of the coastline in the Bay of Port-Bouet, which seek a new equilibrium position by readapting its shore relative to the longshore drift. As a result, a new up drift zone has developed, resulting in a general enhancement of the concavity of the bay of Port-Bouet.

Zro Bi G.F.,Center University Of Recherche Et Dapplication En Tele Detection Curat | Okaingni J.-C.,Félix Houphouët-Boigny National Polytechnic Institute | Kouame K.F.,Center University Of Recherche Et Dapplication En Tele Detection Curat
Revue Francaise de Photogrammetrie et de Teledetection | Year: 2011

In Côte d'Ivoire, the agricultural production can be increased and diversified thanks to wetlands. In fact, these soils are wet every times and they occupy large areas in each region. The main objective set for this study is to mapping them in the region of lakes in the centre of the country in order to evaluate later their fertility. To reach this study's objective, we applied the Spectral Angle Mapper approach which is a method based on the spectral similarity between entities. So, the application of this approach needs to generate some spectres of reference. These spectres have been extracted directly and automatically from the ASTER imagery using the Pixel Purity Index (PPI) method. To determine the specific contribution of the SAM approach in the mapping of wetlands, we compared the results obtained here to those generated by the Maximum Likelihood classification method (used as reference). Both classification methods have been realized with the same ROI. The evaluation of the results proves that the SAM (Kappa = 0,94) described the ground reality better than the Maximum Likelihood (Kappa = 0,88). Also, the SAM approach has been distinguished by the best user accuracy concerning the different components of wetlands.

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