Côte d’Ivoire is currently experiencing strong growth in the mining sector. Identifying the formations present in our subsoil is therefore essential for mining recovery. It is in this context that we conducted s...Côte d’Ivoire is currently experiencing strong growth in the mining sector. Identifying the formations present in our subsoil is therefore essential for mining recovery. It is in this context that we conducted studies on the formations present in the locality of Guintéguéla. It is located in the northwest of Côte d’Ivoire in the bafing region. The aim of this work was to determine the petrographic and structural characteristics of the formations of the area. The methodology began with documentation and then followed petrography and structural analysis work on the macroscopic and microscopic levels. We observed six groups of rocks: granitoids, amphibolites, orthogneiss, quartzites (poor and rich in magnetites), volcano-sediments and filonian rocks. Metamorphism is of amphibolite to granulite facies. However, volcano-sediments must be associated with the green schist facies. With regard to the structural, structures and microstructures such as foliation;fractures;sigmoidal figures reveal that the studied area was affected by ductile and also brittle tectonics whose main directions are oriented along the shear corridor, so N-S to NNW-SSE.展开更多
Flood events occurrences and frequencies in the world are of immense worry for the stability of the economy and life safety. Africa continent is the third continent the most negatively affected by the flood events aft...Flood events occurrences and frequencies in the world are of immense worry for the stability of the economy and life safety. Africa continent is the third continent the most negatively affected by the flood events after Asia and Europe. Eastern Africa is the most hit in Africa. However, Africa continent is at the early stage in term of flood forecasting models development and implementation. Very few hydrological models for flood forecasting are available and implemented in Africa for the flood mitigation. And for the majority of the cases, they need to be improved because of the time evolution. Flash flood in Bamako (Mali) has been putting both human life and the economy in jeopardy. Studying this phenomenon, as to propose applicable solutions for its alleviation in Bamako is a great concern. Therefore, it is of upmost importance to know the existing scientific works related to this situation in Mali and elsewhere. The main aim was to point out the various solutions implemented by various local and international institutions, in order to fight against the flood events. Two types of methods are used for the flood events adaptation: the structural and non-structural methods. The structural methods are essentially based on the implementation of the structures like the dams, dykes, levees, etc. The problem of these methods is that they may reduce the volume of water that will inundate the area but are not efficient for the prediction of the coming floods and cannot alert the population with any lead time in advance. The non-structural methods are the one allowing to perform the prediction with acceptable lead time. They used the hydrological rainfall-runoff models and are the widely methods used for the flood adaptation. This review is more accentuated on the various types non-structural methods and their application in African countries in general and West African countries in particular with their strengths and weaknesses. Hydrologiska Byråns Vattenbalansavdelning (HBV), Hydrologic Engineer Center Hydrologic Model System (HEC-HMS) and Soil and Water Assessment Tool (SWAT) are the hydrological models that are the most widely used in West Africa for the purpose of flood forecasting. The easily way of calibration and the weak number of input data make these models appropriate for the West Africa region where the data are scarce and often with bad quality. These models when implemented and applied, can predict the coming floods, allow the population to adapt and mitigate the flood events and reduce considerably the impacts of floods especially in terms of loss of life.展开更多
文摘Côte d’Ivoire is currently experiencing strong growth in the mining sector. Identifying the formations present in our subsoil is therefore essential for mining recovery. It is in this context that we conducted studies on the formations present in the locality of Guintéguéla. It is located in the northwest of Côte d’Ivoire in the bafing region. The aim of this work was to determine the petrographic and structural characteristics of the formations of the area. The methodology began with documentation and then followed petrography and structural analysis work on the macroscopic and microscopic levels. We observed six groups of rocks: granitoids, amphibolites, orthogneiss, quartzites (poor and rich in magnetites), volcano-sediments and filonian rocks. Metamorphism is of amphibolite to granulite facies. However, volcano-sediments must be associated with the green schist facies. With regard to the structural, structures and microstructures such as foliation;fractures;sigmoidal figures reveal that the studied area was affected by ductile and also brittle tectonics whose main directions are oriented along the shear corridor, so N-S to NNW-SSE.
文摘Flood events occurrences and frequencies in the world are of immense worry for the stability of the economy and life safety. Africa continent is the third continent the most negatively affected by the flood events after Asia and Europe. Eastern Africa is the most hit in Africa. However, Africa continent is at the early stage in term of flood forecasting models development and implementation. Very few hydrological models for flood forecasting are available and implemented in Africa for the flood mitigation. And for the majority of the cases, they need to be improved because of the time evolution. Flash flood in Bamako (Mali) has been putting both human life and the economy in jeopardy. Studying this phenomenon, as to propose applicable solutions for its alleviation in Bamako is a great concern. Therefore, it is of upmost importance to know the existing scientific works related to this situation in Mali and elsewhere. The main aim was to point out the various solutions implemented by various local and international institutions, in order to fight against the flood events. Two types of methods are used for the flood events adaptation: the structural and non-structural methods. The structural methods are essentially based on the implementation of the structures like the dams, dykes, levees, etc. The problem of these methods is that they may reduce the volume of water that will inundate the area but are not efficient for the prediction of the coming floods and cannot alert the population with any lead time in advance. The non-structural methods are the one allowing to perform the prediction with acceptable lead time. They used the hydrological rainfall-runoff models and are the widely methods used for the flood adaptation. This review is more accentuated on the various types non-structural methods and their application in African countries in general and West African countries in particular with their strengths and weaknesses. Hydrologiska Byråns Vattenbalansavdelning (HBV), Hydrologic Engineer Center Hydrologic Model System (HEC-HMS) and Soil and Water Assessment Tool (SWAT) are the hydrological models that are the most widely used in West Africa for the purpose of flood forecasting. The easily way of calibration and the weak number of input data make these models appropriate for the West Africa region where the data are scarce and often with bad quality. These models when implemented and applied, can predict the coming floods, allow the population to adapt and mitigate the flood events and reduce considerably the impacts of floods especially in terms of loss of life.
