http://197.159.135.214/jspui/handle/123456789/8 2026-07-14T04:19:05Z 2026-07-14T04:19:05Z Konko, Yawo http://197.159.135.214/jspui/handle/123456789/1263 2026-07-13T12:53:30Z 2023-09-01T00:00:00Z

Climate Change Induced Sea Level Rise along the Coastland of Togo Konko, Yawo Global warming is a worldwide phenomenon with disastrous implications ranging from ocean warming and glacier melting to sea level rise and coastal damage. In recent decades, the majority of the world's coastal countries have seen tremendous population growth in their coastal districts. Coastal erosion is growing increasingly common as global temperatures rise, displacing coastal inhabitants and damaging towns and socioeconomic infrastructure, making sustainable management of coastal areas extremely difficult. One means for sustainable management and decision-making is to have information on the trend of climatic parameters at the local scale, the settlement pattern, the spatial distribution and dynamics of coastal peoples, the coastal erosion kinematics, the coastal erosion hotspots, the coastal vulnerability to sea level rise and inundation, and the coastal vulnerability to sea level rise and inundation. This research contributes to the understanding of the range of climatic characteristics, spatial distribution and dynamics of coastal peoples, coastal erosion kinematics, and coastal sensitivity to sea level rise and inundation in Togo, West Africa. Images from satellites (Landsat and Sentinel-2), population data, field data, geographical data, and ground truth Climatic data, specifically precipitation, temperature, wind speed, sunshine, and tidal gauge, were used from 1988 to 2020. The Mann-Kendall test and Sen's slope test were used to analyse climate trends, while the Object-Based Image Analysis method was used to map settlement areas. The Support Vector Machine method was used to extract the shoreline, and the kinematics were evaluated using the statistical linear regression method.The InVEST Coastal Vulnerability model was used to assess coastal vulnerability to sea level rise and inundation. Temperature and sea level rise showed a substantial annual trend, according to the findings. The temperature analysis showed an increase of trend of 0. 038 °C/year while the tidal gauge data analysis showed an increase of trend of 13.75 mm/year. The other annual climatic parameters trend record variability which are not significant. However, the monthly analysis revealed the months of the year in which the trends are significant. According to statistical analysis of settlement dynamics, Togo's Maritime region, which had a population of 1,042,385 people in 1980, experienced population increase ranging from 2.06% to 11.85% between 1988 and 2020. The equivalent yearly expansion rate is 6.15 ha/year from 1988 to 2000, 23.41 ha/year from 2000 to 2015, and 40.16 ha/year from 2015 to 2020. In 2022, the Maritime region has reached a population of 3,534,991 people. In addition, near the sea, the pattern of settlement areas is compacted with high density of peoples. In the inland this pattern is dispersed. In terms of shoreline kinematics, the Togolese coast has an average erosion rate ranging from 1.66 to 5.25 m per year. Four erosion hotspots were recorded respectively on transect of Alogavi, Devi-Kinme, Agbavi, and Baguida. One accretion hotspot was recorded in the port area towards Adawlato. For coastal vulnerability model, high vulnerability is observed on the Baguida-Agbodrafo section, moderate vulnerability is observed in the Adawlato area and Agbodrafo-Aneho section, the low vulnerability is located in the port area. According to the findings, land in Togo's coastal zone is in great demand, the rate of settlement is increasing, and the temperature and sea level are rising. Taking this information into account can help to determine the extent of climate change phenomena and draw up suitable coastal management and adaptation plans at the country scale. A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use and the Federal University of Technology, Minna, Nigeria, in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Climate Change and Human Habitat

2023-09-01T00:00:00Z Asonibare, Femi Oluwatosin http://197.159.135.214/jspui/handle/123456789/1262 2026-07-13T12:31:40Z 2024-06-01T00:00:00Z

Evaluation of Projected Distribution of New Urban Climates and Its Implications for Nigeria Asonibare, Femi Oluwatosin Responding to the threats of climate change by cities requires taking relevant actions that will communicate future conditions in reliable and effective manner for sustainable and transformational climate actions. As the population of urban areas in Nigeria continues to rise and changes in climate condition continue to have profound implications on the urban residents, a better understanding of the implication of these changes has informed this study. The study presents the current and future climatic conditions of major Nigerian cities in the past and the implications for future sustainable city related actions. The future climates of the cities were identified in the past under the different representative concentration pathways RCP4.5 (mitigation scenario), RCP8.5 (emissions continuing to rise throughout the 21st century). The climate similarity was calculated using CMIP5 data set which is a downscaled and biased-corrected projections of future climate for total monthly precipitation and average temperature (running mean of 2030s) and (running mean of 2050s). The results revealed that the climate of the cities in the current and future periods will be similar to conditions of another place on the globe during the historical period; Kano city will experience even more drastic changes because of the low level of similarity which is an indication of climate novelty; the new places found with similar temperature conditions are generally to the south of the corresponding cities thus indicating warming. The results also revealed that for temperature indices, the highest warming in minimum temperature is in Kano and Abuja while reduction in the number of cool nights and days occurred in all the cities. Precipitation indices show that the highest increase in the total precipitation is in Lagos at 124mm per decade while Kano shows a reduction of (-95mm per decade). A significantly increasing trend in the hottest day and warmest nights and the decreasing trends in the occurrence of cool days is an indication of warming for the cities. These are indications of increased exposure of the urban areas to climate disasters such as floods, heatwaves, and in Kano, water scarcity. By providing information on the future or current conditions of the cities in the historical period, land managers and city planners will understand and contextualize the future. Drawing from the interaction between cities and their analogues, the study highlighted sustainable city related actions such as the incorporations of urban designs and policies to enhance human thermal comfort as adaptation and solution strategies. While future research might apply qualitative studies and additional data to support the analogue results, our findings can guide the understanding and application of the analogue approach into environmental issues in Nigeria and other West African countries in accordance to sustainable city goals (SDG 11). A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use and the Federal University of Technology, Minna, Nigeria, in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Climate Change and Human Habitat

2024-06-01T00:00:00Z Kolotioloma, Yeo http://197.159.135.214/jspui/handle/123456789/1260 2026-06-25T12:01:40Z 2025-07-01T00:00:00Z

Impact of Climate Variability on Atmospheric Drivers of major Dust Storms over North Africa Kolotioloma, Yeo Dust storms over North Africa represent a critical component of the regional and global climate system, influencing radiation balance, precipitation processes, ecosystem functioning, and human health. Despite their importance, recent studies suggest a multidecadal decline in dust activity across the region, though the driving mechanisms remain debated. This study investigates the spatiotemporal trends in North African dust storm frequency over the past four decades and explores the meteorological and climate drivers underlying these changes using a combination of observational datasets, reanalysis products, and statistical and machine learning methods. Seasonal and annual dust frequency trends derived from surface visibility records reveal a pronounced decrease in dust activity, particularly across the Sahel and central Sahara. Using Theil-Sen trend estimation and Mann-Kendall significance testing, we detect statistically significant declines in surface wind speeds and increases in vegetation cover (leaf area index) and precipitation, especially between 10°N and 15°N. Concurrently, the Saharan Heat Low (SHL) shows signs of intensification and expansion, suggesting possible suppression of dust uplift due to modifications in regional circulation and thermodynamic stability. Correlation analyses further highlight strong seasonal associations between dust storm frequency and drivers such as 10-m wind speed, precipitation, SHL strength, and climate indices (Atlantic Multidecadal Oscillation (AMO), North Atlantic Oscillation (NAO)). A Self-Organizing Map (SOM) classification of sea level pressure and 925 hPa wind patterns during dust storm days reveals dominant atmospheric configurations associated with dust generation, with a clear seasonality and regional preference in SOM node activation. Additionally, Long Short-Term Memory (LSTM) models using climatic and environmental predictors demonstrate skill in reconstructing the historical evolution of dust storms, reinforcing the predictability of dust activity based on climate variability. Overall, the results support the hypothesis that recent declines in North African dust storm activity are linked to a combination of decreased surface wind stress, increased vegetation and rainfall, and changes in the SHL and large-scale climate drivers influence. These findings provide an updated understanding of dust-climate interactions and underscore the importance of land-atmosphere coupling and climate teleconnections in shaping dust variability. A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use and the Federal University of Technology, Akure, Nigeria, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree in West African Climate Systems

2025-07-01T00:00:00Z Yamoula, Dametoti http://197.159.135.214/jspui/handle/123456789/1259 2026-06-25T11:49:33Z 2025-06-01T00:00:00Z

Ocean-Atmosphere interactions in Northwest African and Gulf of Guinea Coastal Upwelling Systems Yamoula, Dametoti The Ocean and Atmosphere interaction is a complex system that requires particular attention in coastal upwelling systems due to their nutrient supply, biological productivity, influence on local weather patterns and regional climate variability, and socio-economic importance. The present study investigates the behaviour of ocean, atmosphere, and their interactions in the coastal upwelling systems of Northwest Africa and Gulf of Guinea during ocean cooling and warming episodes, with a focus on the dynamical and interannual variability of Senegal-Mauritania and Gulf of Guinea upwelling regions. Multiple datasets including different physical and biogeochemical variables, several upwelling indices and statistical tools were used. Results highlighted the seasonal dynamic and interannual variability of two upwelling systems modulated by both local and remote forcings such as wind stress-driven Ekman dynamics, mesoscale and cyclonic eddies, regional ocean ocean currents, Equatorial dynamics including Kelvin and Rossby waves and coastal trapped waves, and large-scale climate drivers. The results also underlined the influence of other geographical and environmental factors such as coastal shape and orientation, the geographical position of upwelling system, the motion of Intertropical convergence zone, and Azores and Saint Helena high pression systems that modulated pression and temperature gradients. The study identified marine heat waves, which are characterized by weakened Ekman transport and suppressed vertical mixing, as emerging stressors of coastal upwelling dynamics. These events significantly impact coastal marine ecosystem productivity, surface air temperature, and precipitation, underscoring the importance of addressing them in local weather predictions. The findings also demonstrate the ongoing limitations of the latest generations of the Coupled Model Intercomparison Project Phases 5 and 6 (CMIP5 and CMIP6) in capturing coastal processes and upwelling features, and call for the use of more powerful artificial intelligence predictive models, such as long short-term memory and convolutional neural networks (LSTM-CNN), to improve weather predictions and reduce uncertainties in climate model simulations in coastal upwelling regions. A Thesis submitted to the West African Science Service Centre on Climate Change and Adapted Land Use and the Federal University of Technology, Akure, Nigeria, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree in West African Climate Systems

2025-06-01T00:00:00Z