Afrique de l'Ouest | EPFL Graph Search

L’Afrique de l’Ouest est une région terrestre couvrant toute la partie occidentale de l’Afrique subsaharienne. Elle comprend approximativement les pays côtiers au nord du golfe de Guinée jusqu’au fleuve Sénégal, les pays couverts par le bassin du fleuve Niger ainsi que les pays de l’arrière-pays sahélien. Berceau des empires successifs du Ghana, du Mali et songhaï, l'Afrique de l’Ouest est un ensemble de pays qui possèdent des influences et un héritage communs. Le système de parenté à plaisanterie qui lie encore aujourd'hui les ethnies et groupes sociaux ouest-africains entre eux en est un exemple frappant. L'autorité impériale s’exerçait à travers le contrôle du commerce transsaharien, la production d'or et de sel. Son déclin s'amorce au avec le développement du commerce maritime. Morcelée et affaiblie après la bataille de Tondibi, l'Afrique de l'Ouest subit la colonisation européenne et américaine à la fin du et durant la première partie du . Certains fondements de la civilisatio

Analysis of the West African Power Pool (WAPP) and its development potential

First of all, it is necessary to specify that this study is an academic work carried out by a student. The hypothesis and the line of reasoning that aect the results obtained are proposed in the context of a master thesis. Electricity supply is a big challenge for West Africa. Indeed, the state members of the Economic Community of West African States (ECOWAS) face many problem of electricity as their production and distribution systems are not enough developed and reliable. A good and reliable electricity supply could allow to develop the industries and improve the attractiveness of the region. The purpose of the West African Power Pool (WAPP) is to develop the electricity sector in West Africa and guarantee a reliable and continuous electricity supply at a competitive cost. Creating an open market for the whole region seems to be the best strategy to achieve these goals. This kind of market could decrease the electricity price by the wholesale purchase of energy, a better resources management and the building of large centralized power plants. Investors can be attracted to invest in new power plants and develop the sector. The objective of the study is to analyze the benets of dierent electricity supply strategies for each country. An autarkic strategy for which each country use its local plants to produce electricity. An open market strategy for which the region is considered as a unique area with an open market.A part of independence strategy for which an open market is in place but the importing countries should produce a certain part of their electricity locally. Moreover a strategy introducing renewables technologies is assessed to evaluate the economical impact on an open market of these technologies. To evaluate these strategies, the expansion of the power pool is planned and evaluate on an economical point of view. The existing power pool is consider and candidate plants are added depending on the strategy and the country. In West Africa, the mainly used plants are thermal plants using natural gas, heavy fuel or diesel and some hydroelectric plants. The expansion is optimized using the software PLANELEC by the minimization of the net present cost (NPC). The economical evaluation is made on the NPC and the levelized cost of electricity (LCOE). The results demonstrate that the open market strategy provides the lowest LCOE. So all the countries will benet the creation of a market. The most used technology are combined cycle power plants and gas turbines using natural gas as a fuel. The renewable energy strategy will slightly increase the LCOE of the open market as these technologies are more expensive.

2019

Contributing to the Quality of PV Solar Modules in West Africa

In this work, we present the set up of a testing facility for photovoltaic (PV) modules and other PV system components in Dakar, Senegal. This creation is the result of a collaboration between the Polytechnic Schools of Dakar (ESP) and Lausanne (EPFL) aiming at improving the quality of PV systems by selecting components with sufficient quality. This testing center should also contribute to the education of all actors involved in the PV sector and contribute to research activities on the aging and failure mode analysis of PV modules exposed to sub-Saharian climates such as the hot semiarid climate of Dakar region but also those of the Economic Community of West African States (ECOWAS) region, including Senegal.

WIP GmbH2019

A field-based modelling framework of the ecohydrology of schistosomiasis

Francisco Javier Perez Saez

Successful control of schistosomiasis, a water-borne parasitic disease, is challenged by the intricacy of the wormâs lifecycle, which depends on aquatic snail intermediate hosts, and involves environmental, ecologic, and socio-economic factors. Current strategies rely on deworming through mass drug administration which however do not protect against reinfection and the persistence of hotspots. It is recognized that multifaceted approaches will be necessary to reach elimination, whose development will require a renewed focus on the diseaseâs social-ecological drivers. Taking cue from the hydrological underpinning of these drivers, this Thesis aims at developing an ecohydrological approach to schistosomiasis with a view to identifying and exploiting the points in which its cycle can be broken. Schistosomiasis is a poverty-reinforcing disease affecting more than 150 million people in sub-Saharan Africa, being the parasitic disease causing the largest health burden after malaria. However, the impairing morbidity it causes has been undervalued in the past, qualifying it as a neglected tropical disease. Moreover, water resources development often exacerbate transmission, posing scientific and ethical challenges in addressing the ensuing trade-off between economic development and public health. The relevance of this Thesisâ work lies in furthering tools to offset this trade-off by unlocking the predictive appraisal of the social-ecological drivers of transmission. An integration of fieldwork applied in Burkina Faso (West Africa) and theoretical methods are employed to address this aim. This Thesis establishes the use of spatially explicit mathematical models of schistosomiasis at the national-scale, allowing to study the effect of human mobility and spatial heterogeneity of transmission parameters. Weekly ecological samplings of snail abundance and continuous environmental monitoring were preformed at three sites along the countryâs climatic gradient, leveraged through ecological modelling. A novel methodology for the large-scale prediction of river network ephemerality allowed for refined snail species distribution models, and the analysis of the diseaseâs geography in link with socio-economic covariates. Finally, surveys and participatory workshops shed light on local-scale water contact patterns. The obtained results substantiate the stance that hydrology is a first-order control of disease transmission. Stability analysis of the spatially explicit model generated additional insight into the impact of the expansion of suitable snail habitat due to water resources development, highlighting the interplay between local and country-wide effects driven by human mobility. Models of snail ecology revealed key hydrological drivers, and disputed density feedbacks. Uncovered phase shifts between permanent and ephemeral habitats were adequately reproduced at the national scale through model regionalization. Characterization and predictions of hydrological ephemerality improved the estimation of the snailsâ ecological range, mirroring the diseaseâs geography. Finally a national-scale association between ephemerality and disease risk was observed, possibly due to human-water contacts aggregation, as supported by preliminary results at village-level. The future incorporation of these ecohydrological findings into spatially explicit models of schistosomiasis is considered promising for optimizing control strategies and attaining disease elimination.

EPFL2018

Analysis of the West African Power Pool (WAPP) and its development potential

2019

A field-based modelling framework of the ecohydrology of schistosomiasis

Francisco Javier Perez Saez

EPFL2018