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Journal of Water Resource and Protection 2017年第12期9卷 1403-1413页

作者： Brou Loukou Alexis Kouassi kouakou Lazare konan kouakou seraphin Kouadio Zile Alex konan Koffi Felix Kamagate Bamory Universite Jean Lorougnon Guede DaloaCote d’Ivoire Universite Nangui-Abrogoua AbidjanCote d’Ivoire

Water resources management is nowadays a significant stake for the world. However, missing or bad quality of the hydro-climatic historical data available of the studied area makes sometimes hydrological studies difficult. Generally, conceptual rain-flow models are designed to bring an appropriate answer with the correction of gaps and prediction of the flows. Historical hydro-climatic data of the Ity station, located on Cavally River, contain gaps which must be bridged. This study aims to establish a rainfall-runoff model through artificial neural networks for filling the gaps into the flow data series of the hydrometric station of Ity on the watershed of Cavally River. A multi-layer perceptron of feed forwards with two entries (monthly average rain and evapotranspiration) and an exit (flows) was established with flow evapotranspiration data. Comparison of the criteria of performance of the various architectures of the neural network model showed that architecture 2-3-1 gives best results. This architecture provides Nash coefficients of 75.79% and correlation linear coefficient of 95.64% for the calibration and Nash coefficients of 73.32% and correlation linear coefficient of 98.33% for the validation. The correlations between simulated flows and observed flows are strong. The correlation coefficients are 83.89% and 83.08% respectively for the calibration and validation.

关键词： Rain-Flow Modeling Artificial Neural Network Cavally River Cote d’Ivoire

Indices of Water Quality and Pesticide Monitoring Survey in Lake of Western Cote d’Ivoire and Its Human Risk Assessment

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Natural Resources 2020年第2期11卷 46-69页

作者： Kouame kouakou Benoit konan kouakou seraphin konan Koffi Felix Boussou Koffi Charles Kouame Kouame Martin Dibi Brou Laboratory of Geosciences and Environment University Jean Lorougnon GuedeDaloaCote d’Ivoire Laboratory of Ecology Biodiversity and EvolutionUniversity Jean Lorougnon GuedeDaloaCote d’Ivoire

The aims of the work were to study the current quality of the water in Lake DOHOU used for drinking water supply through several physical, chemical analyses and using water quality indices (WQI). In addition, the question was whether the populations are at risk after drinking water of lake following a reduction of 50% and 75% in the median and maximum values of pesticides. Thus, the results of the pesticide monitoring program were incorporated into probabilistic human health risk assessment exercises. Water samples were collected over a period of one year. Pesticides were subjected to solid phase extraction and then analyzed using gas chromatography coupled to tandem mass spectroscopy. The other parameters were measured according to conventional methods. The results showed that the most frequently detected pesticides were aldicarb (79%), simazine (79%) and monolinuron (44%). They also showed the mean values of concentrations exceeding 1.5 μg/L. Metoxuron detected at a frequency of 29% showed the maximum average concentration (13.46 μg/L). Nearly 98% of the sampling points had at least one substance with an average concentration above the quality standard (0.1 μg/L) and 80% did not meet the total concentration standards. Cumulative risk quotient estimates after 50% or 75% abatement for frequently identified pesticides were greater than unity when extreme?values for adults and children were considered. To determine the suitability of water for aquatic life, drinking water consumption and drinking water production, the water quality index (WQI), the heavy metal pollution (HPI) and the heavy metal evaluation (HEI) were calculated. The poor quality of the water was mainly related to pesticides, organic matter and microbiological parameters. Most of the nutrients and metals studied were often below the standards of drinking water and aquatic life. The Water Quality Index (WQI) has shown that water quality is degrading for these three modes of use and ranges from poor to m

关键词： Pesticides Health Risk Assessment Water Quality Index Heavy Metal Index

1D-2D Hydraulic Modeling of a Diversion Channel on the Cavally River in Zouan-Hounien,Cote d’Ivoire

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Journal of Water Resource and Protection 2019年第8期11卷 1036-1048页

作者： Kouassi kouakou Lazare Brou Loukou Alexis Yao Affoue Berthe Kouadio Zile Alex konan kouakou seraphin konan Koffi Felix Koffi Berenger Department of Geology University Jean Lorougnon GUEDEDaloaCote d’Ivoire

On the Cavally River, located on the border between C?te d’Ivoire and Liberia, several hydraulic structures such as bridges and diversion channels are planned to be made in recent years in the operating perimeter of the Ity mining company. A 1D-2D hydraulic model was developed to design a diversion channel to cut a meander of the Cavally River in order to ensure hydraulic operation similar to the initial conditions of the river (water levels, flow and velocities). This model was designed with a flow rate of 240 m3/s and a Manning coefficient of 0.052 m1/3·s-1 for the minor bed and 0.06 m1/3·s-1 for the major bed. The results from the hydraulic model show that the hydraulic conditions (water levels, velocities) in the channel before and after the diversion remain almost like those of the Cavally River.

关键词： Hydraulic Modeling Diversion Channel Cavally River Ity Cote d’Ivoire

Prospects for Minimizing the Potential Environmental Impacts of the Hydro-Agricultural Dam of M’Bahiakro(Cote d’Ivoire)

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Journal of Water Resource and Protection 2013年第9期5卷 847-853页

作者： Lazare kouakou Kouassi Innocent Kouassi Kouame seraphin kouakou konan Brou Dibi Soumahoro Moussa Diakaria Kone Dago Gnakri Laboratoire des Sciences de l’eau et de l’Environnement Universite Jean Lorougnon GuedeDaloaCote d’Ivoire Laboratoire Geosciences et Environnement Universite Nangui AbrogouaAbidjanCote d’Ivoire Projet d’Aménagement Hydroagricole de la Vallee du N’Zi ONDR_MINAGRIDimbokroCote d’Ivoire Office National de l’Eau Potable(ONEP) Direction des Ressources en EauAbidjanCote d’Ivoire

This study aims at characterizing the physical environment and suggesting solutions for a better management of the hydro-agricultural dam of M’Bahiakro which is being constructed over the N’Zi River and is the first inflatable dam in Cote d’Ivoire. In this survey, data related to hydrology, characteristics of the dam and the irrigated rice production area were obtained with the Water Resources Agency and the National Office of Rice Development of Cote d’Ivoire. Physicochemical parameters of the N’Zi River were collected seasonally at three monitoring stations. Results showed that the N’Zi River is characterized by a high water level period from April to November and a low water level period from November to April. The gap between the low flows and the high flows is important (about 206 m3/s on average). The annual average flow is 40 m3/s with a standard deviation of 32.52 m3/s and a variation coefficient of 0.88. The SAR average value (1.63) and the average conductivity (78.44 μS/cm) showed that waters of the N’Zi River are of high quality to be used for irrigation. Suspended sediment concentrations do not present significant difference along the river. But the seasonal variations are important;they are higher during the rainy seasons (45.8 mg/L on average) than in the dry seasons (17.7 mg/L on average). The annual solid flux of the N’Zi River is 41897 tons, i.e. 15810 m3 of sediments. The annual sediment flux is important and can lead to high depositions in the line-shaped reservoir of the dam and that calls for attention to control the silting up of the reservoir. Great efforts concerning interdisciplinary approaches, as well as extensive and intensive field work are needed in order to better manage the hydro-agricultural dam of M’Bahiakro.

关键词： Hydrology Irrigation Dam Suspended Sediment N’Zi River

Qualitative Assessment and Typology of the Water Resource Used for the Production of Drinking Water in Duékoué, Western Côte d’Ivoire

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Journal of Geoscience and Environment Protection 2019年第5期7卷 212-231页

作者： Kouamé kouakou Benoit konan kouakou Séraphin Attoungbre kouakou Severin konan Koffi Félix Boussou Koffi Charles Kouamé Kouamé Martin Laboratory of Geosciences and Environment University Jean Lorougnon Guédé Daloa C&#244 te d’Ivoire Laboratory of Ecology Biodiversity and Evolution University Jean Lorougnon Guédé Daloa C&#244 te d’Ivoire

The objective of this study was to evaluate the typology of water through physicochemical and bacteriological characterization with the aim of highlighting its vulnerability as a drinking water resource. The methodology adopted was to evaluate the level of pollution by monitoring the spatiotemporal variation of the water pollution indicator levels of Lake Dohou. The sampling frequency is monthly for one year, from November 2017 to October 2018, in order to obtain a fairly representative image of water quality and its seasonal evolution in eight (8) well-defined stations. The parameters were determined using the standard methods defined by the French Association for Standardization (AFNOR). This study shows that the waters are acidic, with an average pH of 5.81 and a low electrical conductivity of between 42.67 ± 4.30 and 59.62 ± 21.84 μ***-1. At all stations, seasonal mean water transparencies are low (<1 m). It is also noted that 99.7% of the water samples collected had total nitrogen (TN) levels above the limit of 4 mg.L-1. All of the lake’s waters have non-compliant BOD5 (2.L-1) for raw water intended for the production of drinking water. Sites D6 and D7 have COD/BOD5 ratio greater than 3, which indicates the presence of non-biodegradable organic matter in these areas. Total coliforms, Escherichia coli and Enterococci were present in 100% (28/28) water samples at concentrations ranging from 2300 to 173,000 CFU/100 mL, from 100 to 1650 CFU/100 mL and from 20 to 1140 CFU 1/100 mL respectively. For Salmonella pathogens, they were detected in 50% of the dry season samples and in 100% of the rainy season samples. This almost permanent presence of this pathogenic germ denotes a poor quality of water with reference to this parameter. The presence of total coliform and other microbial contaminants suggests that supplied water is highly contaminated with pathogens and great reservoirs for them. Principal component analysis (PCA) of the physicochemical data set allowed de

关键词： Dohou Lake Water Quality Coliform Fecal Coliform Physico-Chemical Parameters Typology and Variation

Classification of Hourly Clearness Index of Solar Radiation in the District of Yamoussoukro

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Energy and Power Engineering 2019年第5期11卷 220-231页

作者： Siaman Paule Carine Yeboua Yao N’Goran kouakou konan Laboratory of Electricity and Energy Conversion (ECEN) Polytechnic National Institute Felix Houphouet-Boigny (INP-HB) Yamoussoukro C&ocirc te d’Ivoire Laboratory of Physics of Condensed Matter and Technology (LPMCT) UFR SSMT University Félix Houphouet-Boigny Abidjan C&ocirc te d’Ivoire

The exploitation of systems using solar energy as a source of energy is not fluctuations free because of short passage of clouds on solar radiation. The amplitude, the persistence and the frequency of these fluctuations should be analyzed with appropriate tools, instead of focusing on their location over time. The analysis of these fluctuations should use the instantaneous clearness index whose distribution is given as a first approximation which is independent not only of the season but also of the site. It is important to evaluate the potential solar energy in a region. Indeed such evaluation helps the decision-makers in their reflections on agricultural or photovoltaic solar projects. Then this study was conducted for a predictive purpose. The method used in our work combines the classification method which is the hierarchical ascending classification and two partitioning methods, the principal component?analysis and the K-means method. The partitioning method enabled to?achieve a number of well-known situations (in advance) that are representative of the day. The study was based on the data of a climatic weather station in the district of Yamoussoukro located in the center region of Côte d’Ivoire during the 2017 year. Using the clearness index, the study allowed the classification of the solar radiation in the region. Thus, it showed that only 346 days of the 365 days in 2017 were classified (95%). We identified three clusters of days, the cloudy sky (29%), the partly cloudy sky?(32%) and the clear sky (39%). The statistical tests used for the characterization?of these clusters will be detailed in a future study.

关键词： Clearness Index Hierarchical Clustering Principal Component Analysis K-Means Method Classification

Evaluation of Pollution Due to Gold Mining at Ity-Floleu Area in Sub-Prefecture of Zouan-Hounien, Western Côte d’Ivoire

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Journal of Geoscience and Environment Protection 2019年第12期7卷 20-41页

作者： Gbamélé Kouassi Serge konan kouakou Séraphin Kouassi kouakou Lazare Brou Loukou Alexis konan Koffi Félix Bini Kouamé Dongui Laboratory of Geosciences and Environment University Jean Lorougnon Guede Daloa Côte d’Ivoire Departement of Geology University Jean Lorougnon Guede Daloa Côte d’Ivoire Laboratory of Ecology Biodiversity and Evolution University Jean Lorougnon Guede Daloa Côte d’Ivoire Laboratory of Environment Chemistry and Materials University Jean Lorougnon Guede Daloa Côte d’Ivoire

This study aims to evaluate the mineral pollution of a gold mining environment in the sub-Prefecture of Zouan-Hounien (C?;te d’Ivoire). Samples were taken from surface water and flesh and skin samples of the Cavally River fish species over a period of two successive years. Concentrations in major elements, trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn), nutrients () and physico-chemical parameters in situ were measured. The results obtained show that the surface waters have very low pH with an average of 5.70. For nutrient salts, the deterioration of water quality in the study area is mainly related to alterations by nitrates, phosphates and sulphates. The concentrations of Fe, Cu, Hg and Pb are above the existing standards (international, FAO/WHO) for the majority of the stations, thus causing the deterioration of the surface water quality. Therefore, their use for agricultural irrigation could have negative impact on the health of the population and on biodiversity. Regarding the bioindicating species, the results obtained after analysis of samples showed that the fish (carp and machoiron) have Fe, Cu, Hg and Pb concentrations higher than the existing standards (international, FAO/WHO) exposing consumers to high health risks. This study showed good correlation between the high values of surface water turbidity and the proximity of gold washing sites. The use of the principal component analysis (PCA) of the physicochemical dataset revealed comparable behaviors for certain minerals within the groups (Fe, K, Mg, Mn and Na) and (As, Cd, Cu, Ni, Pb, Zn and Ca) in water. The Ascending Hierarchical Classification (AHC) analysis has defined three different classes of surface water in the study area. The presence of mineral trace elements in these receiving environments is of natural origin but would be strongly accentuated by human activities.

关键词： Cavally River Fish Gold Mining Major Elements Nutritious Salts Surface Water Trace Elements

Land Use Dynamics in the Department of Séguéla, Northwestern Côte D’Ivoire

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Advances in Remote Sensing 2022年第3期12卷 63-79页

作者： Arthur Brice konan-Waidhet kouakou Hervé Kouassi Kouamé Elyass Kanga Laboratory of Science and Technology of Environment Jean Lorougnon Guédé University Daloa C&#244 te d’Ivoire

Land use monitoring occupies a very important place in the analysis of the dynamics of the earth system. It helps to understand the organization and helps to provide relevant elements for the establishment of diagnoses and the development of environmental forecasts. The objective of this study is to follow the evolution of the agricultural landscape in the department of Séguéla from 1988 to 2020 and to make a prediction for 2050, in order to manage the spaces reasonably. The methodology adopted is based on the one hand on the processing of satellite images for the analysis of land cover and on the other hand on predictive modeling (LCM model) by 2050. The results obtained show that the land use maps produced after processing the satellite images made it possible to highlight the dynamics of the agricultural landscape in this part of the Worodougou region. During the period 1988 to 2020, we witness an increase in the area of cultivated territory as well as a slight reduction in wooded savannas which are largely made up of perennial crops (cashew trees, cocoa trees, coffee trees, etc.). These two aforementioned classes have respective annual rates of change of 2.42% and −0.44%. A scenario modeling land cover changes in 2050 with an overall accuracy of 80.35% revealed a continued growth of crops and fallows to the detriment of natural forests and wooded savannas.

关键词： Satellite Images Land Use LCM Model Land Cover Change Séguéla

Dimensioning of an Anaerobic Digester for the Treatment of Chicken Manure and for the Production of Biogas: The Case Study of a Chicken Farm in Yaokokoroko (Côte d’Ivoire)

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Green and Sustainable Chemistry 2022年第4期12卷 91-103页

作者： kouakou Adjoumani Rodrigue Ehouman Ahissan Donatien konan Affoué Tindo Sylvie Teki Adjoba Marie-Emmanuelle Kouadio Marc Cyril Adou kouakou Eric konan Gbangbo Remis Laboratoire de Thermodynamique et de Physico-Chimie du Milieu (LTPCM) UFR Sciences Fondamentales Appliquées Université Nangui Abrogoua Abidjan C&#244 te d’Ivoire Département de Formation et de Recherche des Sciences de la Terre et des Ressources Minières Ressources en Eaux et Risques Hydrologiques Institut National Polytechnique Felix Houphou&#235 t-Boigny Yamoussoukro C&#244 te d’Ivoire Institut de Recherche sur les Energies Nouvelles Université Nangui Abrogoua Abidjan C&#244 te d’Ivoire Laboratoire des Procédés Industriels de Synthèse de l’Environnement et des énergies Nouvelles (LAPISEN) Institut National Polytechnique Houphou&#235 t-Boigny Yamoussoukro C&#244 te d’Ivoire

This study allowed us to highlight the level of pollution of a BAYA River water near several poultry farms and the sizing of an anaerobic digester that will be able to treat chicken manure from a poultry farm (BRIN FOUNDATION). To evaluate this pollution, the parameters such as ammonium (NH4+), Phosphate (PO43-), Biochemical Oxygen Demand (DBO5) and Nitrate (NO3-) were determined. For sampling point P1, the concentrations in mg/L of these parameters are (25.00 ± 4.25), (0.40 ± 0.20), (98.00 ± 6.35) and (96.00 ± 5.35), respectively. On the other hand, for sampling point P2, the concentrations in mg/L of these parameters are respectively (33.00 ± 9.05), (0.70 ± 0.12), (123 ± 7.13) and (93 ± 7.10). These values indicate a strong organic pollution of the BAYA River. The determination of the different concentrations of the organic pollution parameters allowed us to evaluate the degradation and the quality of the water of the BAYA River water, by the poultry activity. However, considering the physicochemical properties of the waste (chicken manure), which is the main source of organic pollution, we have considered an energy recovery through the production of biogas. This requires the design, sizing, and implementation of an anaerobic digester in a poultry farm. Therefore, the project would require the construction of an adapted masonry type anaerobic digester with a capacity of 10 m3.

关键词： Biogas Organic Pollution Surface Water Biodigester Chicken Manure Anaerobic Digestion

Characterization of a Multimodal and Multispectral Led Imager: Application to Organic Polymer’s Microspheres with Diameter Φ = 10.2 μm

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Optics and Photonics Journal 2016年第7期6卷 171-183页

作者： Marcel A. Agnero Jérémie T. Zoueu kouakou konan Laboratoire d’Instrumentation d’Image et Spectroscopie Institut National Polytechnique Félix Houphou&#235 t-Boigny Yamoussoukro C&#244 te d’Ivoire Laboratoire de Physique de la Matière Condensée et Technologie University Félix Houphou&#235 t-Boigny Abidjan C&#244 te d’Ivoire

Multispectral microscopy enables information enhancement in the study of specimens because of the large spectral band used in this technique. A low cost multimode multispectral microscope using a camera and a set of quasi-monochromatic Light Emitting Diodes (LEDs) ranging from ultraviolet to near-infrared wavelengths as illumination sources was constructed. But the use of a large spectral band provided by non-monochromatic sources induces variation of focal plan of the imager due to chromatic aberration which rises up the diffraction effects and blurs the images causing shadow around them. It results in discrepancies between standard spectra and extracted spectra with microscope. So we need to calibrate that instrument to be a standard one. We proceed with two types of images comparison to choose the reference wavelength for image acquisition where diffraction effect is more reduced. At each wavelength chosen as a reference, one image is well contrasted. First, we compare the thirteen well contrasted images to identify that presenting more reduced shadow. In second time, we determine the mean of the shadow size over the images from each set. The correction of the discrepancies required measurements on filters using a standard spectrometer and the microscope in transmission mode and reflection mode. To evaluate the capacity of our device to transmit information in frequency domain, its modulation transfer function is evaluated. Multivariate analysis is used to test its capacity to recognize properties of well-known sample. The wavelength 700 nm was chosen to be the reference for the image acquisition, because at this wavelength the images are well contrasted. The measurement made on the filters suggested correction coefficients in transmission mode and reflection mode. The experimental instrument recognized the microsphere’s properties and led to the extraction of the standard transmittance and reflectance spectra. Therefore, this microscope is used as a conventional

关键词： Multispectral Imaging Reference Wavelength Correction Coefficients Modulation Transfer Function