Spatio-temporal study of rainfall and temperatures in Guinea: case of N'Zérékoré

Abstract

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