La thèse met en évidence un effet climatique accélérateur des migrations interrégionales au Sénégal. Le changement climatique, notamment, lorsqu’il est de nature progressive, ne suffit pas généralement, à lui seul, à « produire » des migrations humaines. Il interagit avec des facteurs contextuels d’ordre socio-économique, culturel, démographique, politico-institutionnel, environnemental… dans les processus migratoires en exacerbant la vulnérabilité initiale des populations. Ainsi, les politiques devraient se situer à la fois sur des questions (i) de développement (pauvreté et inégalités) en agissant sur l’environnement d’action et les acteurs respectivement de manière cohérente et extensive ; mais également, (ii) d’économie du climat par la réduction de la vulnérabilité physico-climatique à travers des politiques d’atténuation et d’adaptation du milieu et des populations face au changement climatique.

This paper aims to estimate the total effect of climate variability on interregional migration flows in Senegal. We match regional climate data at origin, represented by normalised rainfall and normalised temperatures (maximum and minimum), with regional migration flow data from Senegal’s Agence Nationale de la Statistique et de la Démographie (ANSD) censuses to construct a panel database covering the five-yearly internal migration waves of 1976, 1988, 2001 and 2013. Using a gravity equation model where migration flows are explained by measures of climatic variability at origin, controlled for geographical, socioeconomic and demographic factors traditionally identified in the literature. Our results show that only negative precipitation anomalies at the origin area act as a push factor and accelerate emigration. In the predominantly agricultural regions, rainfall deficits appear, alongside traditional socioeconomic variables, as an additional significant factor shaping mobility across the country.

This paper aims to estimate the total effect of climate variability on inter-regional migration flows in Senegal. We match regional climate data at origin, represented by normalised rainfall and normalised temperatures (maximum and minimum), with regional migration flow data from Senegal's Agence Nationale de la Statistique et de la Démographie (ANSD) censuses to construct a panel database covering the five-yearly internal migration waves of 1976, 1988, 2001 and 2013. Using a gravity equation model where migration flows are explained by measures of climatic variability at origin, controlled for geographical, socio-economic and demographic factors traditionally identified in the literature. Our results show that only negative precipitation anomalies at the origin area act as a push factor and accelerate emigration. In the predominantly agricultural regions, rainfall deficits appear, alongside traditional socio-economic variables, as an additional significant factor shaping mobility across the country.

Artisanal gold mining in Doko, Guinea, has caused severe environmental degradation and soil contamination by potentially toxic metals. This study evaluated the phytoremediation potential of indigenous species growing on contaminated sites. Soil and plant samples (roots and shoots) were collected from six artisanal mining sites, selecting 12 dominant native species based on abundance and ecological relevance. In total, 358 samples were analyzed. Metal concentrations (As, Pb, Cu, Ni, Zn, Cd, Sb, Hg, and Fe) were measured by inductively coupled plasma mass spectrometry (ICP‐MS). Phytoremediation efficiency was assessed using the bioconcentration factor (BCF), translocation factor (TF), and biological accumulation coefficient (BAC). Soils showed severe contamination, with arsenic and lead reaching 550 and 2300 mg/kg, exceeding WHO/FAO guidelines by 27‐ and 23‐fold, respectively. Arsenic was the main ecological risk contributor. No species met hyperaccumulator criteria. However, several species exhibited promising phytoremediation traits. Xanthocercis zambesiaca showed a BCF > 1 for Pb, indicating phytostabilization potential. Acacia ataxacantha , Hyptis suaveolens , and Mitragyna inermis showed TF > 1 for several metals, suggesting effective translocation. Multivariate analysis highlighted Mimosa pigra , X. zambesiaca , and Detarium senegalense as influencing metal mobility. Overall, Doko's native flora shows strong potential for phytostabilization and assisted phytoextraction, offering a realistic nature‐based solution for rehabilitating artisanal gold mining sites.