From medium-resolution satellite images (Landsat TM, ETM+ and OLI), the spatial dynamics of land cover and land use are highlighted. The objective of this study is to quantify the evolution of land use in the watershe...From medium-resolution satellite images (Landsat TM, ETM+ and OLI), the spatial dynamics of land cover and land use are highlighted. The objective of this study is to quantify the evolution of land use in the watershed of the Lobo River upstream of Nibéhibé between 1986 and 2019 in order to analyze the impacts of human activities on the landscape. The study method was based, on the one hand, on the processing of satellite images, for the analysis of the dynamics of land use and, on the other hand, on the CA-Markov model, for the prediction of land use by 2050. It emerged from this study that the land use maps produced made it possible to highlight the spatio-temporal dynamics of land use on the basin. For the period from 1986 to 2019, there is a decrease in the area of forests in favor of built-bare ground and crops and fallows. A land use scenario for the years 2019 and 2050 was simulated with an accuracy of 87.11%. The regressive trend in forests seems to continue in the future with current land use practices.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
In order to better identify spatially the areas at risk of flooding for the riparian populations of Grand-Bassam during strong floods, a study aimed at developing hazard and vulnerability maps from RADAR Sentinel-1 an...In order to better identify spatially the areas at risk of flooding for the riparian populations of Grand-Bassam during strong floods, a study aimed at developing hazard and vulnerability maps from RADAR Sentinel-1 and optical images Sentinel-2 has been put in place. The flood hazard study highlighted the flooded areas in Grand-Bassam. These areas represent 747.7 ha, or 1.02% of the total surface. The vulnerability map produced using the maximum likelihood method identified eight (8) land use classes. These are the classes Water, Dense forest, Secondary forest, Swamp forest, Industrial crops, Food crops, Habitats and bare soils. It made it possible to highlight the socio-economic interests of Grand-Bassam. The flood risk map developed from the intersection of the themes of the vulnerability map and that of the hazard has enabled the recognition of risk areas which are located near the source of the risk (Comoé River) and at low altitudes. These are Moossou, Petit Paris, Quartier Phare and Quartier France.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
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 diagnose...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.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
The threat of agro-industrial exploitations on the quality of groundwater resources has become a major concern for the world’s population, mainly in agricultural areas. To solve this problem, several methods such as ...The threat of agro-industrial exploitations on the quality of groundwater resources has become a major concern for the world’s population, mainly in agricultural areas. To solve this problem, several methods such as vulnerability to pollutants and statistics methods, have been adopted to protect these groundwaters. In this study, statistical tests were used to determine the likely source of pollutants in the groundwater resources. First, we made a comparative analysis and then analyzed pollutants parameters using Kohonen self-organizing map (SOM) which allows basic on the similarity to help out any correlation between the physic-chemical parameters. To validate these results, a land use map was developed to identify the sources of pollutants in production functions of different activities taking place on the catchment area. The results indicate very high levels of certain pollutants such as NO3-, Cl- and SO42- with generally higher than World Health Organization (WHO) standards values. These high levels observed could be attributed to the generally free nature of aquifers alteration and sedimentary formations in areas of high agro-industrial production. The analysis of the data from SOM method reveals a strong correlation between pollutants (NO3-, SO42-,Cl- ) and conductivity showing the likely origin of these surface pollutants,an origin that is linked to the existence of larges agro-industrials exploitations. These results are reinforced by those of the overlay map of the sampling sites on the land use map, which shows a strong coincidence between high values of pollutants and production areas of the pollutants that are agro-industrial exploitations. These areas of coincidence are observed in the north where found banana’s industrials plantations that are less visible and mostly in the southwest part where is one of the largest oil palm plantations in the world (36,000 hectares).展开更多
文摘From medium-resolution satellite images (Landsat TM, ETM+ and OLI), the spatial dynamics of land cover and land use are highlighted. The objective of this study is to quantify the evolution of land use in the watershed of the Lobo River upstream of Nibéhibé between 1986 and 2019 in order to analyze the impacts of human activities on the landscape. The study method was based, on the one hand, on the processing of satellite images, for the analysis of the dynamics of land use and, on the other hand, on the CA-Markov model, for the prediction of land use by 2050. It emerged from this study that the land use maps produced made it possible to highlight the spatio-temporal dynamics of land use on the basin. For the period from 1986 to 2019, there is a decrease in the area of forests in favor of built-bare ground and crops and fallows. A land use scenario for the years 2019 and 2050 was simulated with an accuracy of 87.11%. The regressive trend in forests seems to continue in the future with current land use practices.
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In order to better identify spatially the areas at risk of flooding for the riparian populations of Grand-Bassam during strong floods, a study aimed at developing hazard and vulnerability maps from RADAR Sentinel-1 and optical images Sentinel-2 has been put in place. The flood hazard study highlighted the flooded areas in Grand-Bassam. These areas represent 747.7 ha, or 1.02% of the total surface. The vulnerability map produced using the maximum likelihood method identified eight (8) land use classes. These are the classes Water, Dense forest, Secondary forest, Swamp forest, Industrial crops, Food crops, Habitats and bare soils. It made it possible to highlight the socio-economic interests of Grand-Bassam. The flood risk map developed from the intersection of the themes of the vulnerability map and that of the hazard has enabled the recognition of risk areas which are located near the source of the risk (Comoé River) and at low altitudes. These are Moossou, Petit Paris, Quartier Phare and Quartier France.
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.
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.
基金the International Foundation for Science(IFS)for funding this research.
文摘The threat of agro-industrial exploitations on the quality of groundwater resources has become a major concern for the world’s population, mainly in agricultural areas. To solve this problem, several methods such as vulnerability to pollutants and statistics methods, have been adopted to protect these groundwaters. In this study, statistical tests were used to determine the likely source of pollutants in the groundwater resources. First, we made a comparative analysis and then analyzed pollutants parameters using Kohonen self-organizing map (SOM) which allows basic on the similarity to help out any correlation between the physic-chemical parameters. To validate these results, a land use map was developed to identify the sources of pollutants in production functions of different activities taking place on the catchment area. The results indicate very high levels of certain pollutants such as NO3-, Cl- and SO42- with generally higher than World Health Organization (WHO) standards values. These high levels observed could be attributed to the generally free nature of aquifers alteration and sedimentary formations in areas of high agro-industrial production. The analysis of the data from SOM method reveals a strong correlation between pollutants (NO3-, SO42-,Cl- ) and conductivity showing the likely origin of these surface pollutants,an origin that is linked to the existence of larges agro-industrials exploitations. These results are reinforced by those of the overlay map of the sampling sites on the land use map, which shows a strong coincidence between high values of pollutants and production areas of the pollutants that are agro-industrial exploitations. These areas of coincidence are observed in the north where found banana’s industrials plantations that are less visible and mostly in the southwest part where is one of the largest oil palm plantations in the world (36,000 hectares).
