scholarly journals Variabilite Des Extremes Pluviometriques Sur Le Bassin Versant De La Riviere Bia (Sud-Est, Cote d’Ivoire)

2018 ◽  
Vol 14 (2) ◽  
pp. 134
Author(s):  
Kouassi Kan Martin ◽  
Kouassi Kouakou Lazare ◽  
Yao Koffi Blaise ◽  
Meledje N'diaye Hermann ◽  
Biemi Jean ◽  
...  

Climate change is a reality which affects many climatic variables, including precipitation. The objective of this article is to study the extreme rain variability from a historical database (1941 - 2000). For this purpose, eleven (11) rainfall indices were calculated at the Adiaké, Bianouan, Ayamé, and Agnibilekro rainfall stations in Côte d'Ivoire. Due to lack of data on daily rainfall on the Ghanaian section of watershed, nine (9) monthly precipitations indices were estimated from monthly rainfall at the Enshi and Buakuc stations. The trend analysis of the precipitations indices show that a generalized downward was most significant in Adiaké compared to other stations. Furthermore, indices extreme thresholding (P99, P99p, P99,5 and P99,5p) have experienced a stable trend and a stationary evolution. All steps were detected in the non-stationary indices mostly observed after 1980 (late break) and before 1960 (precocious break).

VertigO ◽  
2013 ◽  
Author(s):  
Tanina Drissa Soro ◽  
Bernard Djè Kouakou ◽  
Ernest Ahoussi Kouassi ◽  
Gbombélé Soro ◽  
Amani Michel Kouassi ◽  
...  

2019 ◽  
pp. 124-139
Author(s):  
Pierre-Yves Bourgin

Cette étude présente la mise au point d'un modèle intégré du fonctionnement hydrologique du bassin versant total du Sassandra en Côte d'Ivoire (environ 75 000 km2). Ce modèle permet d'analyser les effets des aménagements existants et planifiés sur les débits. Il repose sur le couplage d'un modèle d'allocation des ressources en eau avec un modèle pluie-débit. Le modèle repose sur une discrétisation en huit sous-bassins versants, pour lesquels les débits mensuels ont été reconstitués grâce à des méthodes hydrologiques simples à mettre en œuvre et robustes, donc bien adaptées au contexte opérationnel. Les principales incertitudes des résultats de modélisation proviennent de la faible disponibilité des données, de la simplicité des outils et méthodes utilisés, et de la non-stationnarité liée à la rupture climatique observée sur la zone d'étude et ses effets sur la robustesse du paramétrage et les performances du modèle pluie-débit. L'acceptation de ces limitations est justifiée par les bénéfices tirés de l'utilisation du modèle à des fins de planification. Les impacts des aménagements à l'amont de Buyo se traduisent par une augmentation bien plus marquée de la puissance garantie que de l'énergie moyenne sur les ouvrages aval. Ce résultat est dû à l'augmentation de la capacité totale de stockage, donc une capacité accrue à passer les épisodes de sécheresse, tandis qu'en année moyenne, le niveau de régulation des apports à Buyo est déjà très élevé et ne peut être amélioré que marginalement.


Sécheresse ◽  
2009 ◽  
Vol 20 (3) ◽  
pp. 253-261
Author(s):  
Miessan Germain Adja ◽  
Jean-Patrice Jourda ◽  
Marc Youan Ta ◽  
Koffi Kouame ◽  
Kan Jean Kouame ◽  
...  

2017 ◽  
Vol 13 (5) ◽  
pp. 303
Author(s):  
Fofana Oumar ◽  
Kouassi Ernest Ahoussi ◽  
Avy Stéphane Koffi

This study focuses on mapping and identification of pollution factors in the Kan dam basin in Bouaké (Côte d'Ivoire); All through the use of GIS and field investigations. The consequences of socio-economic development on the Kan dam are important. Indeed, the watershed of the dam appears to be the outlet for all the waters (used and rain) of the town of Bouaké. The mapping of land use in the dam basin allows the identification of nuisance and pollution sources. Mainly five (05) types of nuisance and pollution activities were identified: urbanization (habitat zones); Agriculture (agricultural areas); Fishing (fishing zone); Poultry farming (poultry farming); Cattle breeding (pasture area).


2019 ◽  
Vol 13 (1) ◽  
pp. 574
Author(s):  
Germain Kobenan N'guettia ◽  
Jules Mangoua Oi Mangoua ◽  
Narcisse Kouassi Aboua ◽  
Aristide Gountôh Douagui ◽  
Lanciné Droh Gone

Author(s):  
N'da Samuel ◽  
Yao Marcel Konan ◽  
Trokourey Albert

This work aims to assess the simultaneous effects of the climate change and the hydromorphological modification of Vridi channel on its hydrochemistry. To best estimate, this fact, the seasonal dynamic of the particle size distribution, pH, redox potential, salinity, conductivity, moisture and organic matter contents of Vridi channel sediments have been followed and compared during two different annual periods, where the climate and the hydromorphology of this estuary have been different. The first annual period, covering the period from April 2014 to March 2015, has been characterized by a climatic regime close to the climatic normal of the study area and, this channel had its former hydromorphology. The second period annual, covering the period from October 2018 to September 2019, has been marked by a disruption of the climatic regime throughout Côte d'Ivoire, and this channel presented its modified hydromorphology. A monthly sampling has been done in this channel during each annual period. All These physical and chemical parameters have been determined by the corresponding AFNOR standards. Results have shown that these superficial sediments, with a predominantly sandy texture over the period from April 2014 to March 2015, have presented a texture predominantly of silt and clays over the period from October 2018 to September 2019. The climate change and the recent hydromorphological modification of this ecosystem had simultaneous very few effects on their pH and redox potential over the study period. On the other hand, they have caused an important increase in their salinity, moisture and organic matter contents and, a decrease in their electrical conductivity over the period from October 2018 to September 2019 relative to those determined in these substrates over the period of April 2014 to March 2015. This fact has certainly affected its biodiversity, especially that of its benthic fauna.


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