http://repository.pauwes-cop.net/handle/1/5 Institute for Water and Energy Sciences including Climate Change 2026-07-12T02:25:57Z http://repository.pauwes-cop.net/handle/1/597 Assessing Tropical Cyclones risks in Comoros Islands Using Geospatial Technologies Moutoiwaf, Boussoury Tropical cyclones (TCs) are major natural hazards in the Indian Ocean region, particularly in the Comoros Islands, which are regularly hit by tropical cyclones, the latest of which was Cyclone Kenneth in April 2019. The intensity and extent of TCs and their impacts are likely to increase in the future due to climate change. It is therefore essential to carry out a proper cyclone risk assessment, create risk maps and to identify areas where TCs risks are relatively high to minimize potential losses caused by these cyclones. This study developed a multi-criteria spatial approach to map the levels of TCs risk using geospatial technologies to quantify the degree of risk in all the prefectures of the Comoros. A total of 14 spatial criteria covering three risk components vulnerability and exposure, hazard and mitigation capacity were taken into account. A spatial layer was then generated for each criterion with a weighted score using the Analytic Hierarchy Process (AHP) and ArcGIS. Map were then produced for all risk components, and a final cyclone risk map was produced considering vulnerability, hazard and mitigation capacity components. The maps obtained were then used to identify the spatial extent and levels of risk considering four levels (very high, high, moderate, low and very low). The results indicated that the prefecture of Ouani area was more vulnerable to TCs, due to its low altitude, low slopes, being close to the costs, large number of historical cyclone paths and the high population density. The methodological approach and results were then validated by a qualitative assessment carried out in the field. Finally, cyclone risk reduction strategies were suggested. This study has potential and valuable implications for experts and policymakers as it provides a solid basis for the development of national risk maps and mitigation strategies to reduce the disastrous impacts of TCs 2024-03-22T00:00:00Z http://repository.pauwes-cop.net/handle/1/596 Assessing Future Climate Change on maize Crop Productivity using Aquacrop Model in Southern Mali KONE, Lassina Dit Papa This thesis investigates the seasonal crop biomass and grain yield of rainfed maize in N’Tarla, situated in the southern region of Mali, through simulation using aquacrop model. The average biomass and grain yield of maize under historical period spanning from 1991 to 2020, encompassing a period of 30 years were found to be 5.14 and 2.16 t/ha, respectively. Trendline analyses reveal a slight decreasing trend for both maize biomass and grain yield, indicating potential challenges to future agricultural productivity. Moreover, significant changes in maize yields were observed. In addition, the ability of CanESM2 downscaled by RCA4 to simulate the future climate of the region was evaluated, demonstrating satisfactory performance. The projected climate trends indicate a continual rise in global temperatures, with the region experiencing increases of up to 6.0°C and 2.7°C in minimum and maximum temperatures, respectively, by 2080 under the RCP 8.5 scenario. Furthermore, rainfall is expected to decrease by 41.6% within the region by 2050 under the RCP 4.5 scenario. The future scenarios highlight the influence of changing rainfall patterns and temperature rise on maize crop yield. A decrease of 0.3% and 1.6% in grain yield was observed under the RCP 4.5 scenarios for the periods 2021-2050 and 2051-2080, respectively, compared to the reference period of 1991-2020. Similarly, all scenarios demonstrated a decrease in biomass yield compared to the baseline period, with the most significant reductions observed under the RCP 4.5 and RCP 8.5 scenarios for the period 2051-2080. Given these findings, it is imperative to adopt adaptation strategies to mitigate the adverse effects of climate change on maize production. Such strategies may include selecting more resilient crop varieties, enhancing water and nutrient management practices, and diversifying production systems to ensure food security and sustainable agricultural development in the face of changing climatic conditions 2024-03-01T00:00:00Z http://repository.pauwes-cop.net/handle/1/595 Spatio-temporal study of rainfall and temperatures in Guinea: case of N'Zérékoré TRAORE, Sidiki The Spatio-temporal study of rainfall and temperatures is capital importance for understanding climatic variations in Guinea, particularly in N’Zérékoré prefecture. The main objective of this research is to understand the climatic trends observed over time in N’Zérékoré prefecture. The applied methodologies include trend analysis using the Mann-Kendall test and Sen's slope estimator, as well as statistical analyses, and were calculated by XLSTAT software included in Excel. Global climate models, such as MIROC6 and ACCESS-CM2, have been used to study future climate projections. Data was collected from various sources, including the N'Zérékoré meteorological station and global climate models were downloaded from the website https://www.worldclim.org/data/cmip6/cmip6climate.html. This study uses various formulas and methods to analyze climate data using MATLAB. Formulas such as Pearson’s correlation, RMSE, MSE, standard deviation, and standardized precipitation and temperature index (Tmax and Tmin), as well as data normalization and arithmetic mean, are essential to evaluate and characterize precisely the statistical series dispersion. GIS software, with the use of its ArcGIS 10.8 version, generates maps of the study area and future projections based on different climate models. The results obtained revealed significant interannual variability in rainfall and maximum and minimum temperatures, highlighting the trends of decreasing rainfall and increasing temperatures signifying the climate change impact on N’Zérékoré region. Seasonal variations of precipitation and temperature (Tmax and Tmin), were also examined, providing valuable information on seasonal climate patterns in the prefecture. The evaluation of different models allowed us to identify MIROC6 and ACCESS-CM2 models for climate scenarios. We used MIROC6 model for precipitation projections and maximum temperature and ACCESS-CM2 model for minimum temperature. In sum, the results of its projections clearly showed that in N’Zérékoré, the clues and signals related to climate change are perceptible in this city with future increases in temperatures (Tmax and Tmin) in the 20s, 40s, 60s, and 80s years to come 2024-01-01T00:00:00Z http://repository.pauwes-cop.net/handle/1/594 ROLE OF URBAN AND PERI-URBAN FOREST ON CLIMATE CHANGE UNDERSTANDING AND MITIGATION IN SAHEL CITIES: EVIDENCE FROM NIAMEY (NIGER REPUBLIC) Souley YACOUBA, Habibou This study examines the critical role of urban and peri-urban forests in mitigating and adapting to climate change in Niger's city of Niamey. The study uses a combination of spatial analysis, remote sensing, and modeling techniques to evaluate changes in Niamey's forest cover, temperature, and population distribution from 1992 to 2023. The results indicate a significant loss of woodland, a concerning rise in maximum and minimum temperatures, and a rapid increase in the urban population. The study emphasizes a substantial negative correlation between vegetation cover and surface temperatures, emphasizing the importance of urban forests in regulating the local microclimate. Additionally, areas with the highest population density coincide with pronounced urban heat islands, increasing the vulnerability of populations to the dangers associated with climate change. This research offers valuable information to inform policies and strategies that promote the sustainable management of urban forests in Niamey to enhance the city's resilience to climate change. 2024-01-01T00:00:00Z