The present study aims to delimit protection perimeters around the “Agbo” river in Agboville in order to reduce the risks of pollution of this water resource. The methodological approach consisted first all in asses...The present study aims to delimit protection perimeters around the “Agbo” river in Agboville in order to reduce the risks of pollution of this water resource. The methodological approach consisted first all in assessing the vulnerability of the resource and then in determining the protection perimeters based on the vulnerability map and previous studies. Five parameters (slope, land use, soil type, annual runoff and drainage density) were used. These parameters were then weighted using the Saaty multicriteria analysis method. The vulnerability map reveals four classes (very low, low, medium and high) with a dominance of the low class (41.35% of the area). Three protection perimeters were delineated (immediate, close and remote). The immediate protection perimeter is delimited at a distance of 200 m around the SODECI water intake on the “Agbo” river and covers the areas with a strong influence on the vulnerability to pollution of the river. The closer protection perimeter at a distance of 1000 m, is represented by the zones with strong influence on the vulnerability of the resource and the direction of water flow in the watershed. Finally, the remote protection perimeter covers a large part of the catchment area with a surface area of 510.36 km2 and takes into account the zones that have an influence on the vulnerability to pollution of the resource. These delimited protection perimeters can serve as a guide for the management and protection of the water intake in Agboville as well as for land use planning in this area.展开更多
The supply of drinking water from aquifers of base remains problematic because of his complexity. The combination of several methods is more adapted for the mapping of water establishment favorable areas. This study i...The supply of drinking water from aquifers of base remains problematic because of his complexity. The combination of several methods is more adapted for the mapping of water establishment favorable areas. This study is focused on water points establishment favorable areas mapping. The methods used are remote sensing, pump tests sheets for determining aquifers and saprolites thickness. To determine the recharge, GR2M Method and drainage density has been used. The digital elevation model (DEM) has been used to generate slopes and drainage density maps. The thematic maps obtained combined under GIS to produce water potentiality map. The results obtained have been with exploitation rates. Three classes of potentialities have been identified. These are classes of high potentialities in groundwater which cover approximately 20% of the study area. It occurs mainly in central areas where there are sedimentary formations usually captured by the drilling. These areas are generally located in the central part, mainly in areas where there is low slope, important with a thick layer of saprolites.展开更多
The protection of aquifers is a major concern for the authorities, especially in areas where there are large agro-industrial exploitations. The objective of this study is to define a new method of aquifer protection b...The protection of aquifers is a major concern for the authorities, especially in areas where there are large agro-industrial exploitations. The objective of this study is to define a new method of aquifer protection based on the characteristics of the structures of aquifers. The intrinsic vulnerability mapping method, PaPRI was used. It is a variant of the PaPRIKa method applied in karstic environment which has been adapted for its application in basement environment. This method uses three factors, including aquifer protection (P), using the soil cover, the unsaturated zone and the thickness of the alteration layer, (R) for the rock type and (I) for infiltration which including slope and drainage density. PAPRI is a method based on the weighting of different factors. The results obtained show 4 classes that evolve from low vulnerability classes (5% of the study area) to high and very high vulnerability classes (58%) and average vulnerability classes (37%). The classes of high and very high vulnerability, which indicate the zones that are very exposed to pollution, are more present in the central-northern part of the study area, with a few appearances towards the south. These zones could be related to topography due to the often very high slopes observed in the area. One of the advantages of this new method lies in the characterization of the alterations that strongly influence the migration of pollutants towards the water tables according to their nature and their thickness.展开更多
Groundwater is an important natural resource for all human activity. Today, due to climate change and population growth, the demand has increased considerably, thus requiring their evaluation to ensure sustainability....Groundwater is an important natural resource for all human activity. Today, due to climate change and population growth, the demand has increased considerably, thus requiring their evaluation to ensure sustainability. However, one of the important but difficult to estimate parameters due to its variability is the recharge. This work aims to map the potential recharge of aquifers in the departments of Yamoussoukro and Toumodi. Saaty’s AHP (Analytical Hierarchy Process) multi-criteria analysis technique was used by integrating different thematic layers. First, a reclassification then weighting of these parameters was made according to their influence in the recharge process. Finally, they were integrated into a GIS to produce the map of potential groundwater recharge zones. The results indicate that the potential high recharge areas represent approximately 43.11% of the area of the study area. These areas appear scattered in the sub-prefecture of Yamoussoukro, Kokoumbo Attiegouakro, Toumodi et Kpouèbo.展开更多
This study focuses on the problem of access to drinking water in the fractured areas of the departments of Yamoussoukro and Toumodi. The problem has become more acute since most of the boreholes drilled have failed. T...This study focuses on the problem of access to drinking water in the fractured areas of the departments of Yamoussoukro and Toumodi. The problem has become more acute since most of the boreholes drilled have failed. The main objective of this study is to map the areas that are favorable for the installation of large boreholes in the departments of Yamoussoukro and Toumodi in order to increase the population’s drinking water needs. Hydroclimatic and cartographic data, technical surveys of boreholes and satellite images were used to conduct this study. The AHP multi-criteria analysis method was adopted. It consists in aggregating the criteria by weighting and allowed to combine these different data to generate maps of groundwater availability, accessibility and exploitability indicators. These different indicators were then considered as criteria and combined using the full aggregation technique to produce the water potential map. These results show that the study area has significant groundwater reserves with nearly 63% of these areas being favorable for the establishment of large flow boreholes. This study provides some answers to the question of groundwater resources and could be used as a decision support tool in the execution of groundwater collection works in the departments of Yamoussoukro and Toumodi in order to avoid the high percentage of drilling failures encountered in past projects.展开更多
Mangrove ecosystems are faced with far more existential threats of erosion than their terrestrial counterparts. Consequences of their degradation vary from decline in edible aquatic stocks, coastal erosion and aquatic...Mangrove ecosystems are faced with far more existential threats of erosion than their terrestrial counterparts. Consequences of their degradation vary from decline in edible aquatic stocks, coastal erosion and aquatic weeds invasion. Mangrove forest dynamics was assessed from multi-temporal analyses of remotely sensed satellite images (mosaics of 1989/90 and 2014/15) within 233,900 hectares. Ground-truthing was accompanied by field measurements in selected forest stands to characterize structure, estimate biomass and carbon pools. With conservation as overriding goal, a socio-economic survey was conducted to underpin the factors influencing mangrove forests over-exploitation and qualitatively assess the sensitivity of the locals to resources decline. The region recorded fifty percent loss of mangrove area during the 25-year period. Low leaf area index (1.02 - 2.52 m<sup>2</sup>·m<sup>-2</sup>) confirms canopy openness. Above-ground root biomass (kg per root) ranged between 110.67 and 382.64. The roots demonstrate capacity to fix up to 176 Mg C ha<sup>-1</sup> with average carbon content of 46 percent. Highest carbon pools were in the Eloka-To forest stands, in near natural conditions. Despite harsh environmental conditions, potential for natural regeneration was evidenced by seedlings density (individuals per m<sup>2</sup>) up to 76. Pilot survey revealed high dependence on mangrove resources for direct income (70 percent) and daily energy needs (60 percent). Despite the heightened awareness of the impending dangers posed by mangrove deforestation and willingness to conserve, riverine communities are incapacitated by lack of viable economic alternatives. External interventions are therefore imperative to achieve conservation goals with long-term implications for climate change adaptation and mitigation.展开更多
This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums—Anoumabo (Marcory) and Adjouffou (Port-Bouet), both located in the southern part of the ...This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums—Anoumabo (Marcory) and Adjouffou (Port-Bouet), both located in the southern part of the city. Twenty-eight representative groundwater samples were collected from different domestic wells within the study area. In addition, water samples were collected from the adjoining surface water bodies—the ébrié lagoon and the Atlantic Ocean. The water samples were also tested for microbial indicators of fecal contamination using the conventional membrane filtration method. The groundwater samples are alkaline to acidic with pH ranging between 4.4 and 8.1. They are slightly mineralized with electrical conductivity, EC values ranging between 388 μS/cm and 1494 μS/cm. The dominant hydrochemical facies are Na-Cl, Na-SO4, Ca-Cl and Ca-SO4. Although, majority of the water samples have anions and cations concentrations conforming to the World Health Organization, alerting levels of nitrate contamination was recorded in the area. About 67 percent of the tested samples have nitrate values greater than the recommended WHO limit for drinking water (NO3 > 50 mg/ι). Exceeding high nitrate concentrations in drinking water have been medically proven to be detrimental to infant health. Microbial analyses reveal bacterial contamination at varying degrees in all of the water wells. The presence of these microbial organisms in the samples is also indicative of the presence of some other disease causing pathogens, responsible for sicknesses like cholera, diarrhea, typhoid, etc. The water wells located within Anoumabo have relatively higher levels of groundwater contaminants in comparison to those located within Adjouffou. This is obviously due to the poor well designs and prevalent unhygienic and poor sanitary habits of its inhabitants. These waters though completely unsuitable for drinking and domestic purposes, can be used for irrigation purposes with very little or no sodium problems.展开更多
文摘The present study aims to delimit protection perimeters around the “Agbo” river in Agboville in order to reduce the risks of pollution of this water resource. The methodological approach consisted first all in assessing the vulnerability of the resource and then in determining the protection perimeters based on the vulnerability map and previous studies. Five parameters (slope, land use, soil type, annual runoff and drainage density) were used. These parameters were then weighted using the Saaty multicriteria analysis method. The vulnerability map reveals four classes (very low, low, medium and high) with a dominance of the low class (41.35% of the area). Three protection perimeters were delineated (immediate, close and remote). The immediate protection perimeter is delimited at a distance of 200 m around the SODECI water intake on the “Agbo” river and covers the areas with a strong influence on the vulnerability to pollution of the river. The closer protection perimeter at a distance of 1000 m, is represented by the zones with strong influence on the vulnerability of the resource and the direction of water flow in the watershed. Finally, the remote protection perimeter covers a large part of the catchment area with a surface area of 510.36 km2 and takes into account the zones that have an influence on the vulnerability to pollution of the resource. These delimited protection perimeters can serve as a guide for the management and protection of the water intake in Agboville as well as for land use planning in this area.
文摘The supply of drinking water from aquifers of base remains problematic because of his complexity. The combination of several methods is more adapted for the mapping of water establishment favorable areas. This study is focused on water points establishment favorable areas mapping. The methods used are remote sensing, pump tests sheets for determining aquifers and saprolites thickness. To determine the recharge, GR2M Method and drainage density has been used. The digital elevation model (DEM) has been used to generate slopes and drainage density maps. The thematic maps obtained combined under GIS to produce water potentiality map. The results obtained have been with exploitation rates. Three classes of potentialities have been identified. These are classes of high potentialities in groundwater which cover approximately 20% of the study area. It occurs mainly in central areas where there are sedimentary formations usually captured by the drilling. These areas are generally located in the central part, mainly in areas where there is low slope, important with a thick layer of saprolites.
文摘The protection of aquifers is a major concern for the authorities, especially in areas where there are large agro-industrial exploitations. The objective of this study is to define a new method of aquifer protection based on the characteristics of the structures of aquifers. The intrinsic vulnerability mapping method, PaPRI was used. It is a variant of the PaPRIKa method applied in karstic environment which has been adapted for its application in basement environment. This method uses three factors, including aquifer protection (P), using the soil cover, the unsaturated zone and the thickness of the alteration layer, (R) for the rock type and (I) for infiltration which including slope and drainage density. PAPRI is a method based on the weighting of different factors. The results obtained show 4 classes that evolve from low vulnerability classes (5% of the study area) to high and very high vulnerability classes (58%) and average vulnerability classes (37%). The classes of high and very high vulnerability, which indicate the zones that are very exposed to pollution, are more present in the central-northern part of the study area, with a few appearances towards the south. These zones could be related to topography due to the often very high slopes observed in the area. One of the advantages of this new method lies in the characterization of the alterations that strongly influence the migration of pollutants towards the water tables according to their nature and their thickness.
文摘Groundwater is an important natural resource for all human activity. Today, due to climate change and population growth, the demand has increased considerably, thus requiring their evaluation to ensure sustainability. However, one of the important but difficult to estimate parameters due to its variability is the recharge. This work aims to map the potential recharge of aquifers in the departments of Yamoussoukro and Toumodi. Saaty’s AHP (Analytical Hierarchy Process) multi-criteria analysis technique was used by integrating different thematic layers. First, a reclassification then weighting of these parameters was made according to their influence in the recharge process. Finally, they were integrated into a GIS to produce the map of potential groundwater recharge zones. The results indicate that the potential high recharge areas represent approximately 43.11% of the area of the study area. These areas appear scattered in the sub-prefecture of Yamoussoukro, Kokoumbo Attiegouakro, Toumodi et Kpouèbo.
文摘This study focuses on the problem of access to drinking water in the fractured areas of the departments of Yamoussoukro and Toumodi. The problem has become more acute since most of the boreholes drilled have failed. The main objective of this study is to map the areas that are favorable for the installation of large boreholes in the departments of Yamoussoukro and Toumodi in order to increase the population’s drinking water needs. Hydroclimatic and cartographic data, technical surveys of boreholes and satellite images were used to conduct this study. The AHP multi-criteria analysis method was adopted. It consists in aggregating the criteria by weighting and allowed to combine these different data to generate maps of groundwater availability, accessibility and exploitability indicators. These different indicators were then considered as criteria and combined using the full aggregation technique to produce the water potential map. These results show that the study area has significant groundwater reserves with nearly 63% of these areas being favorable for the establishment of large flow boreholes. This study provides some answers to the question of groundwater resources and could be used as a decision support tool in the execution of groundwater collection works in the departments of Yamoussoukro and Toumodi in order to avoid the high percentage of drilling failures encountered in past projects.
文摘Mangrove ecosystems are faced with far more existential threats of erosion than their terrestrial counterparts. Consequences of their degradation vary from decline in edible aquatic stocks, coastal erosion and aquatic weeds invasion. Mangrove forest dynamics was assessed from multi-temporal analyses of remotely sensed satellite images (mosaics of 1989/90 and 2014/15) within 233,900 hectares. Ground-truthing was accompanied by field measurements in selected forest stands to characterize structure, estimate biomass and carbon pools. With conservation as overriding goal, a socio-economic survey was conducted to underpin the factors influencing mangrove forests over-exploitation and qualitatively assess the sensitivity of the locals to resources decline. The region recorded fifty percent loss of mangrove area during the 25-year period. Low leaf area index (1.02 - 2.52 m<sup>2</sup>·m<sup>-2</sup>) confirms canopy openness. Above-ground root biomass (kg per root) ranged between 110.67 and 382.64. The roots demonstrate capacity to fix up to 176 Mg C ha<sup>-1</sup> with average carbon content of 46 percent. Highest carbon pools were in the Eloka-To forest stands, in near natural conditions. Despite harsh environmental conditions, potential for natural regeneration was evidenced by seedlings density (individuals per m<sup>2</sup>) up to 76. Pilot survey revealed high dependence on mangrove resources for direct income (70 percent) and daily energy needs (60 percent). Despite the heightened awareness of the impending dangers posed by mangrove deforestation and willingness to conserve, riverine communities are incapacitated by lack of viable economic alternatives. External interventions are therefore imperative to achieve conservation goals with long-term implications for climate change adaptation and mitigation.
文摘This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums—Anoumabo (Marcory) and Adjouffou (Port-Bouet), both located in the southern part of the city. Twenty-eight representative groundwater samples were collected from different domestic wells within the study area. In addition, water samples were collected from the adjoining surface water bodies—the ébrié lagoon and the Atlantic Ocean. The water samples were also tested for microbial indicators of fecal contamination using the conventional membrane filtration method. The groundwater samples are alkaline to acidic with pH ranging between 4.4 and 8.1. They are slightly mineralized with electrical conductivity, EC values ranging between 388 μS/cm and 1494 μS/cm. The dominant hydrochemical facies are Na-Cl, Na-SO4, Ca-Cl and Ca-SO4. Although, majority of the water samples have anions and cations concentrations conforming to the World Health Organization, alerting levels of nitrate contamination was recorded in the area. About 67 percent of the tested samples have nitrate values greater than the recommended WHO limit for drinking water (NO3 > 50 mg/ι). Exceeding high nitrate concentrations in drinking water have been medically proven to be detrimental to infant health. Microbial analyses reveal bacterial contamination at varying degrees in all of the water wells. The presence of these microbial organisms in the samples is also indicative of the presence of some other disease causing pathogens, responsible for sicknesses like cholera, diarrhea, typhoid, etc. The water wells located within Anoumabo have relatively higher levels of groundwater contaminants in comparison to those located within Adjouffou. This is obviously due to the poor well designs and prevalent unhygienic and poor sanitary habits of its inhabitants. These waters though completely unsuitable for drinking and domestic purposes, can be used for irrigation purposes with very little or no sodium problems.
